Gland anatomy: The request could not be satisfied
The Pituitary Gland – Structure – Vasculature
The pituitary gland (the hypophysis) is a major gland of the endocrine system.
It secretes hormones that control the actions of other endocrine organs and various tissues around the body.
In this article, we shall look at the anatomy of the pituitary gland – its position, structure and vascular supply.
Anatomical Position and RelationsFig 1.0 – The pituitary gland.
The pituitary gland is a pea-sized oval structure, suspended from the underside of the brain by the pituitary stalk (known as the infundibulum). It sits within a small depression in the sphenoid bone, known as the sella turcica (‘’Turkish saddle’’).
The superior surface of the gland is covered by a reflection of the dura mater – the diaphragma sellae. This membrane has a central opening which allows passage of the infundibulum.
The gland has several key anatomical relations:
- Anteriorly – sphenoid sinus (the pituitary gland is accessed surgically via the sphenoid sinus, known as a trans-sphenoidal approach).
- Posteriorly – posterior intercavernous sinus, dorsum sellae (posterior wall of the sella turcica), basilar artery and the pons.
- Superiorly – diaphragma sellae (fold of dura mater that covers the pituitary gland), optic chiasm.
- Inferiorly – sphenoid sinus
- Laterally – cavernous sinus.
Clinical Significance: Pituitary Adenoma
A pituitary adenoma is a neoplasm of the pituitary gland. These tumours are usually benign and can be divided into two categories: non-functional tumours and hormone secreting tumours.
As the tumour increases in size, it can compress surrounding structures, such as the optic chiasm. A lesion of the optic chiasm characteristically produces a visual defect known as a bitemporal hemianopia. A pituitary tumour can also cause excessive hormone production, or insufficient hormone production (by destroying the normal glandular tissue).
Definitive treatment of a pituitary adenoma is via trans-sphenoidal surgery. This technique involves gaining access to the gland via the nasal cavity and sphenoid sinus (which is located immediately inferiorly to the gland).
Anatomically, the pituitary gland is a ‘’two-in-one’’ structure consisting of the anterior pituitary and the posterior pituitary. These parts have different embryonic origins and function very differently.
The anterior lobe (adenohypophysis) is derived from an outpouching of the roof of the pharynx, called Rathke’s pouch. It is composed of glandular epithelium and secretes a number of hormones. The lobe can be further divided into three parts:
- Pars anterior – the largest part, responsible for hormone secretion.
- Pars intermedia – a thin epithelial layer that separates the pars anterior from the posterior lobe.
- Pars tuberalis – an upwards extension of the pars anterior that surrounds the anterolateral aspect of the infundibulum.
The release of hormones is under the control of the hypothalamus, which communicates with the gland via neurotransmitters secreted into the hypophyseal portal vessels. These vessels ensure that the hypothalamic hormones remain concentrated, rather than being diluted in the systemic circulation.
The posterior lobe (neurohypophysis) consists of nervous tissue. It arises from the embryonic forebrain, and is, in essence, an extension of the hypothalamus.
Upon stimulation, the posterior lobe secretes two hormones – ADH (responsible for control of blood osmolarity), and oxytocin (involved in parturition and milk secretion). Both of these substances are produced in the supraoptic and paraventricular nuclei of the hypothalamus and then subsequently stored in the posterior pituitary gland, ready for release.Fig 1.2 – The structure of the pituitary gland.
The vasculature of the pituitary gland is complex and unique. Whilst the anterior lobe and posterior lobe have the same venous drainage (anterior and posterior hypophyseal veins), they have an individual arterial supply:
The anterior pituitary gland receives arterial supply from the superior hypophyseal artery (a branch of the internal carotid artery). This vessel first forms a capillary network around the hypothalamus – blood from this network is then transported to a secondary capillary plexus surrounding the anterior pituitary.
Known as the hypophyseal portal system, this structure allows the hypothalamus to communicate with the anterior pituitary via the release of neurotransmitters into the bloodstream.
The infundibulum and posterior pituitary gland receive a rich blood supply from many arteries. Of these, the major vessels are the superior hypophyseal artery, infundibular artery and inferior hypophyseal artery.Fig 1.3 – The blood supply to the anterior and posterior lobes of the pituitary gland.
The Pineal Gland – Structure – Vasculature
The pineal gland is a small endocrine gland located within the brain. Its main secretion is melatonin, which regulates the circadian rhythm of the body. It is also thought to produce hormones that inhibit the action of other endocrine glands in the body.
In this article, we shall look at the anatomy of the pineal gland – its structure, position and vasculature.
Anatomical Structure and Position
The pineal gland is small glandular body, approximately 6mm long. It is shaped like a pine cone, from which its name is derived. There are two types of cells present within the gland:
- Pinealocytes – hormone secreting cells.
- Glial cells – supporting cells.
In middle age, the gland commonly becomes calcified, and can be subsequently identified on radiographs and CT scans of the head.
The pineal gland is a midline structure, located between the two cerebral hemispheres. It is attached by a stalk to the posterior wall of third ventricle. In close proximity to the gland are the superior colliculi of the midbrain – paired structures that play an important role in vision.Fig 1.0 – Sagittal section of the brain, showing the midline position of the pineal gland
The arterial supply to the pineal gland is profuse, second only to the kidney. The posterior choroidal arteries are the main supply; they are a set of 10 branches that arise from the posterior cerebral artery.
Venous drainage is via the internal cerebral veins.
Clinical Relevance: Pineal Gland Tumours
Pineal glands tumours are a diverse group of neoplasms. The most common is a germ cell tumour, which arises from residual embryonic tissue in the gland.
It presents with the classical symptoms of a space occupying lesion – headache, nausea and vomiting. The tumour can also cause Parinaud syndrome – inability to move the eyes upwards – this is due to compression of the superior colliculi. In addition, obstruction of the cerebral aqueduct may produce hydrocephalus.
In children, a pineal gland tumour (which invades and destroys the gland), produces an accelerated onset of puberty. Thus, it is thought that one of the functions of the gland is to inhibit sexual development.
Thyroid gland | anatomy | Britannica
Thyroid gland, endocrine gland that is located in the anterior part of the lower neck, below the larynx (voice box). The thyroid secretes hormones vital to metabolism and growth. Any enlargement of the thyroid, regardless of cause, is called a goitre.
Anatomy of the thyroid gland
The thyroid arises from a downward outpouching of the floor of the pharynx, and a persisting remnant of this migration is known as a thyroglossal duct. The gland itself consists of two oblong lobes lying on either side of the trachea (windpipe) and connected by a narrow band of tissue called the isthmus. In normal adults the thyroid gland weighs 10 to 15 grams (0.4 to 0.5 ounce), though it has the capacity to grow much larger.
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The lobes of the gland, as well as the isthmus, contain many small globular sacs called follicles. The follicles are lined with follicular cells and are filled with a fluid known as colloid that contains the prohormone thyroglobulin. The follicular cells contain the enzymes needed to synthesize thyroglobulin, as well as the enzymes needed to release thyroid hormone from thyroglobulin. When thyroid hormones are needed, thyroglobulin is reabsorbed from the colloid in the follicular lumen into the cells, where it is split into its component parts, including the two thyroid hormones thyroxine (T4) and triiodothyronine (T3). The hormones are then released, passing from the cells into the circulation.
Biochemistry of thyroid hormone
Thyroxine and triiodothyronine contain iodine and are formed from thyronines, which are composed of two molecules of the amino acid tyrosine. (Both iodine and tyrosine are acquired in the diet.) Thyroxine contains four iodine atoms, and triiodothyronine contains three iodine atoms. Because each molecule of tyrosine binds one or two iodine atoms, two tyrosines are used to synthesize both thyroxine and triiodothyronine. These two hormones are the only biologically active substances that contain iodine, and they cannot be produced in the absence of iodine. The process leading to the eventual synthesis of thyroxine and triiodothyronine begins in the thyroid follicular cells, which concentrate iodine from the serum. The iodine is then oxidized and attached to tyrosine residues (forming compounds called iodotyrosines) within thyroglobulin molecules. The iodinated tyrosine residues are then rearranged to form thyroxine and triiodothyronine. Therefore, thyroglobulin serves not only as the structure within which thyroxine and triiodothyronine are synthesized but also as the storage form of the two hormones.
Structural drawing of T3, reverse T3, and T4, showing the synthesis of T3 and reverse T3 from T4.
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Considerably more thyroxine is produced and secreted by the thyroid gland than is triiodothyronine. However, thyroxine is converted to triiodothyronine in many tissues by the action of enzymes called deiodinases. After thyroxine enters a cell, deiodinases located in the cytoplasm remove one of its four iodine atoms, converting it into triiodothyronine. The triiodothyronine either enters the nucleus of the cell or is returned to the circulation. As a result, all of the thyroxine and about 20 percent of the triiodothyronine produced each day come from the thyroid gland. The remaining 80 percent of triiodothyronine comes from deiodination of thyroxine outside of the thyroid. Most if not all of the action of thyroid hormone in its target tissues is exerted by triiodothyronine. Therefore, thyroxine may be considered a circulating precursor of triiodothyronine.
In serum more than 99 percent of the thyroxine and triiodothyronine is bound to one of three proteins. These binding proteins are known as thyroxine-binding globulin, transthyretin (thyroxine-binding prealbumin), and albumin. The remaining thyroxine and triiodothyronine (less than 1 percent) is free, or unbound. When free hormone enters a cell, it is replenished immediately by hormone attached to the binding proteins. The binding proteins serve as reservoirs of the two hormones to protect the tissues from sudden surges of thyroid hormone production and probably also to facilitate delivery of the hormones to the cells of large, solid organs such as the liver.
Essentially all cells in the body are target cells of triiodothyronine. Once triiodothyronine is inside a cell, it enters the nucleus, where it binds to proteins known as nuclear receptors. The triiodothyronine-receptor complexes then bind to deoxyribonucleic acid (DNA) molecules. This results in an increase in the rate at which the affected DNA molecules are transcribed to produce messenger ribonucleic acid (mRNA) molecules and an increase in the rate of synthesis of the protein (translation) coded for by the DNA (by way of the mRNA). Triiodothyronine increases the transcription of DNA molecules that code for many different proteins; however, it also inhibits the transcription of DNA that codes for certain other proteins. The patterns of activation and inhibition differ in different tissue and cell types.
Actions of thyroid hormone
The substances produced in increased quantities in response to triiodothyronine secretion include many enzymes, cell constituents, and hormones. Key among them are proteins that regulate the utilization of nutrients and the consumption of oxygen by the mitochondria of cells. Mitochondria are the sites at which energy is produced in the form of adenosine triphosphate (ATP) or is dissipated in the form of heat. Triiodothyronine activates substances that increase the proportion of energy that is dissipated as heat. It also stimulates carbohydrate utilization, lipid production and metabolism (thereby increasing cholesterol utilization), and central and autonomic nervous system activation, resulting in increased contraction of cardiac muscle and increased heart rate. During fetal life and in infancy this stimulatory activity of triiodothyronine is critically important for normal neural and skeletal growth and development; in both the unborn and the newborn, thyroid deficiency is associated with dwarfism and intellectual disability.
Anatomy of submandibular gland and duct
return to: Sialogram Technique, Bartholin’s duct on normal sialogram, Bartholins duct anatomy: Salivary Ductoplasty
see also: Classification of Salivary Duct Stenosis (Parotid Duct Stricture – Submandibular Duct Stricture)
Case example Submandibular Gland Resection
see also: Salivary Stone Removal with Ductoplasty from Submandibular Gland
and Plunging Ranula Transoral Resection (Sublingual Gland) Aided With Sialendoscopy with Histopathology
Diagram above according to Iowa Sialogram Classification System (Foggia 2020, Thorpe 2020)
Anatomy of Submandibular Gland & Duct and the Submandibular triangle (Level 1b)
- Characterized by an acinar-ductal system (as are all 3 major salivary glands)
- saliva is produced within the acinus which is comprised of pyramidal cells grouped about a central lumen.
- saliva is modified in character as it moves successively from the acini through intercalated ducts, striated ducts and excretory ducts and finally into the oral cavity
- the predominant cell type within the acinus of the submandibular gland is seromucous (in contrast to the parotid which is predominately serous and the sublingual gland in which mucous cells comprise the majority)
- Submandibular triangle (level 1B)
- Borders: anterior and posterior bellies of the digastric muscle and the lower border of the mandibular body
- Contents: submandibular gland, lymph nodes, facial artery, facial vein (crosses the gland superficially)
- the submandibular gland overlies both bellies of the digastric muscle with the posterior border lying near the anterior-inferior aspect of the parotid gland at the mandibular angle
- the marginal mandibular branch of the facial nerve usually overlies the gland as it passes from the cervicofacial branch of the facial nerve to innervate the deep surface of the lower lip depressors lying in a plane deep to platysma and superficial to the submandibular gland fascia
- the upper aspect of the superficial surface of the of the gland lies partly against the submandibular depression on the inner surface of the mandibular body and partially on the mylohyoid muscle
- the deep surface of the gland overlies:
- mylohyoid muscle
- hyoglossus muscle
- styloglossus muscle
- stylohyoid muscle
- posterior belly of the digastric muscle
- the anterior aspect of the submandibular gland splits to surround the posterior aspect of the mylohyoid muscle with a deep extension bordered by the hypglossus muscle and the styloglossus muscle medially and the mylohyoid muscle laterally
- located superiorly to the deep process of the gland are:
- the submandibular ganglion
- the lingual nerve
- located superiorly to the deep process of the gland are:
- located inferiorly to the deep process of the gland is the hypoglossal nerve
- Submandibular (Wharton’s) Duct
- extends from the anterior aspect of the submandibular gland deep to mylohyoid on the lateral surfaces of the hyoglossus muscle and genioglossus muscle, which are lateral to the hypoglossal nerve
- as the duct exits the gland, it lies inferior to the lingual nerve
- as the duct continues distally, the lingual nerve passes below the duct and the crosses it medially, forming a near-complete loop around the duct (see photos at: Salivary Ductoplasty)
- the terminal aspect of the duct lies in contact with the sublingual gland as it lies in a submucosal plane within the floor of mouth
Ultrasound anatomy of submandibular gland (Katz, 2009) see: Salivary Ultrasound
- Location: anterior and caudal to the parotid gland.
- Other structures in the region: Bone – mandible, Muscles – mylohyoid, anterior belly of the digastric, Vessels – facial artery and vein.On oblique view of SMG can see palatine tonsil
- Echostructure: the submandibular gland is more hypoechoic than the parotid gland.
- Appearance: triangular shape with a posterior base. Rarely seen are normal intraglandular ducts. With stimulation (sialogogue), visualization may be easier.
- Wharton’s duct originates from the deep portion of the gland and ascends anteriorly to the floor of the mouth, differentiated from the lingual vessels by color Doppler
Foggia MJ, Peterson J, Maley J, Policeni B, Hoffman HT. Sialographic analysis of parotid ductal abnormalities associated with Sjogren’s syndrome. Oral Dis. 2020 Jul;26(5):912-919. doi: 10.1111/odi.13298. Epub 2020 Mar 3. PMID: 32031309.
Thorpe RK, Foggia MJ, Marcus KS, Policeni B, Maley JE, Hoffman HT. Sialographic Analysis of Radioiodine-Associated Chronic Sialadenitis. Laryngoscope. 2020 Nov 17. doi: 10.1002/lary.29279. Epub ahead of print. PMID: 33200832.
Hoffman H, Funk G, Endres G. Evaluation and surgical treatment of tumors of the salivary glands. In: Themley SE, Ponje WR, Botskis JG, Lindberg RD, eds. Comprehensive Management of Head and Neck Tumors. 2nd ed. Philadelphia, Pa: WB Saunders, 1999
Katz P, Hartl DM, Guerre A. Clinical ultrasound of the salivary glands. Oto Clin N Am. 2009; 42(6):973-1000
Picture, Function, Definition, Location in the Body, and More
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The thyroid is a butterfly-shaped gland that sits low on the front of the neck. Your thyroid lies below your Adam’s apple, along the front of the windpipe. The thyroid has two side lobes, connected by a bridge (isthmus) in the middle. When the thyroid is its normal size, you can’t feel it.
Brownish-red in color, the thyroid is rich with blood vessels. Nerves important for voice quality also pass through the thyroid.
The thyroid secretes several hormones, collectively called thyroid hormones. The main hormone is thyroxine, also called T4. Thyroid hormones act throughout the body, influencing metabolism, growth and development, and body temperature. During infancy and childhood, adequate thyroid hormone is crucial for brain development.
- Goiter: A general term for thyroid swelling. Goiters can be harmless, or can represent iodine deficiency or a condition associated with thyroid inflammation called Hashimoto’s thyroiditis.
- Thyroiditis: Inflammation of the thyroid, usually from a viral infection or autoimmune condition. Thyroiditis can be painful, or have no symptoms at all.
- Hyperthyroidism: Excessive thyroid hormone production. Hyperthyroidism is most often caused by Graves disease or an overactive thyroid nodule.
- Hypothyroidism: Low production of thyroid hormone. Thyroid damage caused by autoimmune disease is the most common cause of hypothyroidism .
- Graves disease: An autoimmune condition in which the thyroid is overstimulated, causing hyperthyroidism.
- Thyroid cancer: An uncommon form of cancer, thyroid cancer is usually curable. Surgery, radiation, and hormone treatments may be used to treat thyroid cancer.
- Thyroid nodule: A small abnormal mass or lump in the thyroid gland. Thyroid nodules are extremely common. Few are cancerous. They may secrete excess hormones, causing hyperthyroidism, or cause no problems.
- Thyroid storm: A rare form of hyperthyroidism in which extremely high thyroid hormone levels cause severe illness.
Anatomy Of The Parotid & Submandibular Glands & Ducts
The major salivary glands, three pairs in total, are found in and around your mouth and throat. The major salivary glands are the parotid, submandibular, and sublingual glands. The parotid glands are located in front and beneath the ear. A duct, called Stensen’s duct, drains saliva from the parotid gland into the mouth, at the area of the upper cheeks. The submandibular glands are found on both sides, just under and deep to the jaw, towards the back of the mouth. This gland produces roughly 70% of the saliva in our mouth. The submandibular duct, called Warhtin’s duct, enter the floor of the mouth under the the front of the tongue. Sublingual glands, meanwhile, reside beneath the tongue, and supply saliva to the floor of the mouth as well. There are many (between 600 to 1,000) tiny glands called minor salivary glands. These glands are 1-2 mm in diameter and coat all the mucousal surfaces or lining of our mouth and throat.
Parotid Surgery Animation
Purpose of salivary gland
Together, the salivary glands produce saliva, which help moisten our mouth, soften the food we chew, initiate digestion, protect the teeth from decay, and help keep the mouth clean by washing away germs. The flow of saliva is stimulated by the presence of food in the mouth, or even the sight and smell of food.
What is the parotid gland?
The parotid glands produce a type of saliva that is “serous” which means it’s more watery and thin. It is has the protein Amylase that helps begin the process of starch digestion. While we are not eating, the parotid glands each contribute to 10% of saliva in the mouth, but when stimulated by eating the saliva each parotid gland produces accounts for 25% of the saliva in the mouth.
Types of cells
There are many different types of cells that make up the small little parts of the gland that produce saliva and secrete it (you can see these different cell types on the diagram). Because of the variety of cell types, there are many different types of tumors and cancers that can develop in the parotid gland. Additionally, because there are several lymph nodes inside the parotid gland, at times skin cancers over the temple, scalp and cheek areas can spread to this area; additionally, lymphomas can occur in these lymph nodes.
The salivary glands are constantly working, and can be affected by many medical conditions, medications, and even not drinking enough water. Infections and inflammation of the gland can cause it to swell up and become painful. Obstruction of the ducts, which can happen because of salivary stones or narrowing of the duct from infection, can cause the saliva to back up into the gland and lead to it to swelling up as well.
If you would like to know more about the salivary glands, schedule a consultation with parotid surgeon Dr. Larian today by calling (888) 687-6118.
Next, learn about parotid & facial nerve anatomy.
Frequently Asked Questions about Parotid Surgery:
At the Center for Advanced Parotid Surgery, our team of medical professionals specializes in performing minimally invasive parotidectomy with a focus on facial nerve preservation and facial reconstruction. Here we’ve put together the most common questions we get from patients.
How Should I Prepare for Surgery?
- Ensure all your questions are answered. Write them down when you think of them.
- You should have a clear idea of exactly what surgery is planned, what will be done, the risks, all your options and what the expected benefits are.
- You should also have a clear expectation of results that is in alignment with the doctor’s expectations as well.
- You should tell your surgeon what medications and supplements (including herbal and OTC medications like ibuprofen) you are currently taking.
- Ensure that you have stopped taking any medication or supplement that our surgeon asks within the proper timeframe.
- If you are not already leading a healthy life, it is best to start doing so several weeks before the surgery, not just before. Be active, eat healthy and quit smoking (if you smoke).
How Long Will I Be Hospitalized?
It really depends upon exactly what was done during the surgery. In most cases, a brief hospital stay of four days or less may be required.
Can a Facelift Be Performed at the Same Time as a Parotid?
In many cases, yes. In fact, it is often safer to do the surgeries concurrently because the parotid surgical procedure carefully traces the facial nerve and positions it safely. Doing a facelift at the same time lowers the chance of accidentally damaging this nerve at a later time because of its shifted position.
Depending on the size of the tumor removed, there may be excess skin on one side of the face that will need to be tightened. To maintain facial symmetry, the other side of the face may also need tightening. So a facelift at this time may be an ideal choice. Dr. Larian and his team will advice you if a facelift is an option for you.
How long does Parotid surgery take?
Most parotidectomies take between 3 and 4 hours.
Do Benign Parotid Tumors Need to Be Removed?
The most common approach to dealing with parotid tumors, even benign ones, is to surgically remove them. These tumors can grow to abnormal sizes that can disfigure the face. More importantly, even a benign parotid tumor can become cancerous if left alone to grow.
Do salivary gland stones go away on their own?
There are a number of non-surgical procedures that often help the stones go away without surgery. If that doesn’t work and the salivary gland is completely blocked and swelling, surgery is the next best step.
How long does it take for a Parotidectomy to heal?
You can plan on one to two weeks for initial incision healing and about six weeks for complete incision healing. Scar creams are advised for use to hasten healing and should be used for the first six weeks. Incisions may continue to change in form for up to two years after surgery, but most scars are hidden behind the jawline and ear and not readily noticeable.
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Prostate Gland Anatomy
The prostate gland is a mass of tissue just below the urinary bladder in males, about the size of a walnut. It is situated in the region called the bladder base. It extends all around the urethra like a doughnut, surrounding the neck of the bladder.
Why is prostate anatomy important?
The prostate in humans is involved in three major disease conditions: benign prostatic hyperplasia, prostatic cancer, and prostatic inflammation.
The earliest descriptions of the anatomy of the prostate date back to the middle of the 1500s, to illustrations published by Andreas Vesalius.
Diagram of prostate from 1538 by Andreas Vesalius.
It has two main components: muscular and glandular, making it a compound gland. It has three lobes, one central and one on each side, the right and the left. It secretes fluids that drain through small tubes called ducts, into the enclosed part of the urethra lying within it.
Lobes of the prostate gland
The shape of the prostate allows it to be subdivided into a base and an apex, an anterior and posterior and two lateral surfaces. The base lies in close proximity to the lower surface of the urinary bladder and faces upwards. The apex points downwards and rests on the upper fascia of the urogenital diaphragm.
- The anterior lobe is solely fibromuscular, without glands.
- The median lobe is cone-shaped, lying between the urethra and the two lateral ejaculatory ducts.
- The lateral lobes are the bulk of the gland, and are separated by the prostatic part of the urethra, joining together behind it.
- The posterior lobe is the part that can be felt through the rectal wall on digital rectal examination.
There are a number of lymph nodes draining this region, such as the periprostatic, hypogastric and three groups of iliac nodes.
Illustration of prostate. Image Credit: Artemida-psy / Shutterstock
Zones of the prostate gland
The tissue of the prostate gland is also divided into three types of zones:
- The peripheral zone: this is the largest, and is located at the back of the prostate near the rectal wall. This is the area that a clinician can feel when performing a digital rectal exam. This is the area where 70% to 80% of all prostate cancers occur.
- The central zone: this is the region around the ejaculatory ducts and is the site least affected by cancer (less than 5%). However, these tumors are typically aggressive and invasive in behavior.
- The transition zone: this surrounds the urethra at the point of entry into the prostate gland. Initially small, it grows throughout life and its increasing size is responsible for the enlargement seen in benign prostatic hyperplasia. About 20% of prostate cancers arise here. Tumors in this region usually are associated with higher levels of PSA and are larger in size. However, they are slow to invade the seminal vesicles or the prostate capsule, and recurrence after treatment is unlikely.
What does the prostate do?
The prostate gland forms part of the male reproductive organs. It secretes a slightly alkaline fluid that is ejected into the urethra during intercourse, at male climax, forming part of the seminal fluid which carries sperm. The prostatic fluid is pushed into the urethra by the muscle in the walls of the prostatic glands. This fluid, in combination with sperm, forms semen, which is eventually ejected through the opening at the end of the penis during ejaculation.
Development of prostate gland
The early human embryo starts to develop prostatic buds from the epithelium covering an area called the urogenital sinus (UGS). These solid epithelial buds grow into the surrounding mesenchyme of the UGS to form cords of cells that eventually form a particular shape corresponding to the lobes of the prostate. The surrounding mesenchyme also forms fibroblasts between the muscle fascicles, and smooth muscle cells, even as the cords develop a lumen beginning from the urethral end. As androgen levels increase, the epithelial cells differentiate and produce more androgen receptors, to synthesize various specific substances.
After birth, the human prostate remains more or less static until puberty. At this point the sudden surge in androgen levels causes an increase in prostate size, which continues to grow slowly over several years. Once the prostate reaches adult size, it stops enlarging. Further size increase is not related to androgen excess, but to aging and a relative deficiency of androgen.
Anatomy and physiology of the paraurethral glands
The urethra of a woman has a length of 3-4 cm and a diameter of 7-8 mm, and practically along its entire length directly adjoins the anterior wall of the vagina. The proximal part of the urethra is separated from the anterior wall of the vagina by a space filled with loose connective tissue, which gradually decreases and the urethra is intimately adhered to the vaginal wall. In this area, the urethra is easily palpable.
The female urethra is surrounded by a large number of paraurethral glands.It has been established that these groin-like glands are homologous to the prostate.
From a historical point of view, it is interesting to note that RegenerideGraaf as early as 1672 described and illustrated a glandular structure around the female urethra, which he called the “female prostate”. Morgagni and then Guerin in 1864 gave a detailed description of diseases of the vulvar glands and passages, and for a long time they went under the name of the Guerin glands. This is followed by observations by Morgagni and Astrue, dated 1875.And in 1880, the American gynecologist Skene, together with Westbrook in J. Obstetrics & Gynecology, described in the most detail the paraurethral passages or glands, which have retained the name of Skene who discovered them to this day. The scientist drew attention to 2 paraurethral ducts (Skene ducts) and emphasized their importance in genital infection. Skene’s work was based on anatomical research and the illustrations that accompany it are still the basis for most of the descriptions in modern textbooks.
HuffmanJW in his work showed that there are multiple (more than two, described by Skene) ducts and sinuses, lined with epithelium, which are mainly emptied into the distal third of the female urethra. These ducts form an extensive network of tubular canals and glands that surround the female urethra, mainly along the posterior and lateral walls. The number of ducts varies widely from 6 to 31. They are usually concentrated in the distal part of the urethra. These data confirm a direct relationship between the localization of the paraurethral glands and the formation of paraurethral cystic diseases.
The terminal branches of some of the large ducts often extend over considerable distances parallel to the urethra and may extend several millimeters into the bladder.
Relatively few paraurethral ducts open into the proximal urethra. There are, however, frequent crypts and lacunae in the mucous membrane of the proximal urethra, which are lined with the same type of epithelium that is lined with the terminal paraurethral glands and tubules. Apparently, such invaginations of the posterior urethra originate from the same embryonic formation from which the large structures found in the distal urethra develop.
The secret of the Sienia glands acts as a protective barrier for the urethra during coitus. It has been suggested that the production of the paraurethral glands during coitus is comparable to the activity of the glands of the male urethra. It is also believed that the secret of these glands has antimicrobial activity, and the glands themselves serve as a mechanism of local protection against microbial invasions.
According to the observations of many authors, the Senian glands undergo significant changes at different periods of a woman’s life: during pregnancy they hypertrophy, in the postpartum period they undergo involution, and in menopause they atrophy.
In the center of the human head, scientists have discovered an organ unknown to science
Photo by, Radiotherapy and Oncology
Scientists from the Netherlands made an amazing discovery: they discovered an organ hidden inside the human head, resembling a set of salivary glands.
It would seem that the structure of the human body was studied up and down centuries ago, but scientists still did not know about the existence of this organ.
The discovery happened by chance, during the examination of patients with prostate cancer using the latest PSMA PET / CT scanner. With contrast tomography with the introduction of radioactive glucose into the blood, this diagnostic tool is found in the body of the tumor.
In this case, he found something else behind the nasopharynx.
Photo author, Radiotherapy and Oncology
Tubular glands, shown with blue arrows, next to other salivary glands, highlighted in orange
“A person has three sets of large salivary glands, but not in this place”, – says radiologist-oncologist Wouter Vogel of the Netherlands Cancer Institute.
“As far as was known, the salivary glands in the nasopharynx are microscopically small. About a thousand of them are evenly distributed over the mucous membrane. So imagine our surprise when we discovered THIS!”
The salivary glands produce the saliva necessary for the digestive system to function. Most of it is divided into three main sets of glands, known as the parotid, submandibular, and sublingual.
There are about a thousand small salivary glands in the human body.They are found throughout the mouth and in the respiratory tract, but are so small that they can only be detected under a microscope.
The previously unseen fourth set of salivary glands discovered by Vogel’s team is much larger and is located behind the nose and above the palate, in the very middle of the head.
Photo author, Radiotherapy and Oncology
This is how the newly discovered glands look in different projections
“The two organs that are highlighted during the examination have all the signs of the salivary glands,” says lead author of the study, oral surgeon Matthijs Walstar from University of Amsterdam.
“We called them tubular glands because they are located above the tubular ridge [the elevation in the nasal part of the pharynx containing the cartilage of the Eustachian tube].
Tubular glands were found in all 100 patients examined with the PSMA PET / CT. Autopsy of two bodies, male and female, also confirmed the existence of a paired structure visible to the naked eye in the form of drainage capillaries in the posterior wall of the nasopharynx.
The video (in English) clearly shows the location of the tubular glands, as well as their structure.
“To the best of our knowledge, this structure has not been previously described in any source,” says a study report published in the journal Radiotherapy and Oncology.
Anatomy of the stomach, structure of the stomach, treatment of the stomach
The stomach is a hollow organ that is adapted for filling with food, initial digestion of food, partial absorption of nutrients with further evacuation of the contents into the duodenum. The stomach is located in the upper part of the abdominal cavity, under the diaphragm, mostly to the left of the midline.
The shape and volume of the stomach depend on the tone of its muscles, on filling it with food, on the state of neighboring organs, and on the position of the body. In the upper part of the stomach, the esophagus flows into it; in the lower part, the duodenum leaves the stomach.
Four parts are isolated in the stomach:
- The cardiac part of the stomach is on top and adjacent to the opening from the esophagus to the stomach, which is called the “cardia”
- The bottom or vault is the part of the stomach that is at the top and forms a kind of dome
- The body of the stomach is the main middle part of the stomach
- The pyloric or pyloric part is located at the entrance to the duodenum, where the sphincter is located, which regulates the flow of the food lump into the duodenum – pylorus
The wall of the stomach consists of four layers:
- mucous membrane
- submucosal layer
- muscle layer
- external serous membrane
The gastric mucosa is a layer on top of which there are cylindrical epithelial cells, under which there is loose connective tissue and then a thin layer of smooth muscles. In the loose connective tissue of the mucous membrane are the glands of the stomach.
There are three types of cells that form these glands. Some of them are called the main ones. These glands produce pepsinogens and chymosin. The next type of cell is called parietal or parietal cells. They synthesize hydrochloric acid and gastromucoprotein. The third type of cell is accessory cells or mucocytes. They produce mucoid secretions. In the area of the pylorus (pylorus) are hormone-active cells.These cells synthesize gastrin.
The gastric mucosa also contains a huge amount of other producing biologically active substances. The role of some of them is still not fully understood. A very important function of the glandular cells of the stomach is to form a protective mucous barrier. Continuous synthesis of gastric mucus is required, which is produced by mucus-forming cells.
This function is stimulated by the activating effect of the autonomic nervous system, insulin, serotonin, prostaglandins. The secretion of mucus increases under the mechanical influence of parts of the food lump that irritate the gastric mucosa. Some medications reduce the mucus-forming function: aspirin (acetylsalicylic acid), non-steroidal anti-inflammatory drugs, etc.
There are contraindications. Read the instructions or consult a specialist.
The cost of an ultrasound of the stomach at the EMC clinic.
Breast structure | Lactating mammary gland | Study
Dr. Donna Geddes of the University of Western Australia, during the ultrasound scan of the lactating mammary glands, began to have doubts about the correctness of the anatomical images in the textbooks.The standard breast model was based on the anatomical dissection of cadavers carried out in 1840 by Sir Astley Cooper. Additional state-of-the-art research has been carried out with the support of Medela and has changed the way we think about the lactating breast.
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A study by the University of Western Australia led to some groundbreaking discoveries that significantly changed much of the previous understanding of the structure of the lactating breast.
Main research results
- The mammary gland has 4 to 18 ductal openings (previously it was thought that there were 15–20 of them).
- Closer to the nipple, the ducts branch out.
- There are no traditionally described lactiferous sinuses.
- The ducts can be positioned closer to the surface of the skin, which allows them to contract more easily.
- Most of the glandular tissue is located within 30 mm of the nipple.
The illustration developed by Medela based on these new discoveries is now used in numerous textbooks and websites.
There are three main points to consider when it comes to lactation.
- A quick initial flow of milk is essential for efficient milk extraction.
- Expression funnels should be sized individually for each mother.
- Hand position is very important when supporting the breast while expressing.
1. A quick and effective initial inflow of milk is very important for its further optimal extraction
Since the study did not confirm the presence of lactiferous sinuses, large volumes of milk cannot be stored in the ducts, therefore, only a very small amount of milk can be extracted before the milk rises. It is known that at the beginning of a feed, the baby suckles quickly, which stimulates the secretion of milk. Research shows that an initial rapid flow of milk then triggers a series of subsequent flushes. In fact, when using a biphasic breast pump at the most comfortable vacuum level, 80% of the milk is withdrawn from the breast in the first 7 minutes (Kent et al 2008).
This is why it is important to ensure that the baby grasps properly in order to stimulate the flow of milk during breastfeeding, as well as the use of a breast pump that can effectively stimulate milk production.
2. Expression funnels must be individually sized
A properly fitting funnel will not constrict superficial milk ducts and will allow effective breast emptying.
3. Hand position with breast support or pumping
Since 65% of the glandular tissue is within 30 mm of the nipple and the milk ducts are quite close to the surface, it is important to consider the position of the hands and fingers when feeding or expressing. Compression of ducts and tissues can impede the free movement of milk from the breast, lead to blockages and, in turn, to swelling of the mammary glands, and then to a decrease in the amount of milk. When milk is not removed from the breast, a protein called feedback lactation inhibitor (FIL) is produced. As the amount of this protein increases, a signal is sent to the hypothalamus to decrease the amount of prolactin, and, accordingly, milk production decreases. To avoid such situations, it is necessary to teach mothers to correctly position the baby so that during feeding or pumping, there is no too strong squeezing of the breast.
Nodular hyperplasia of the thyroid gland | MyPathologyReport.ca
What is thyroid nodular hyperplasia?
Nodular hyperplasia of the thyroid gland is a benign tumor that affects the thyroid gland. Abnormal growth may affect half of the gland (one lobe) or the entire gland (both lobes and the isthmus). Patients with this condition may notice a thickening in the thyroid gland or an enlargement of the entire thyroid gland. Doctors call these growths thyroid nodules.Thyroid nodular hyperplasia is the most common cause of thyroid nodules.
The thyroid gland is a small U-shaped gland located in the front of the neck. It consists of two halves, called lobes, that lie along the trachea and are connected by a narrow strip of thyroid tissue known as the isthmus.
The function of the thyroid gland is to take iodine, which is found in many foods, and convert it into thyroid hormone.Once cooked, the thyroid hormone is released into the bloodstream and transported throughout the body, where they control the body’s metabolism (such as converting oxygen and calories into energy).
Most of the cells in the thyroid gland are called follicular cells. Follicular cells join together to form small, round structures called follicles. Thyroid hormone is stored in a material called a colloid that fills the center of the follicles.
Ultrasound and fine needle aspiration
Doctors often recommend an examination called an ultrasound for patients with a tumor in the thyroid gland or if the entire gland is enlarged. This test allows the doctor to see the inside of the thyroid gland. Ultrasound also allows the doctor to remove a small sample of tissue in a procedure called fine needle aspiration (FNA). This tissue is sent to a pathologist who examines it under a microscope.
How do pathologists make this diagnosis?
The diagnosis of nodular hyperplasia of the thyroid gland can be made after part or all of the thyroid gland has been surgically removed and sent for examination to a pathologist.The examination includes examining the thyroid gland with and without a microscope. When examined without a microscope, the thyroid gland appears larger than usual, and light-colored nodules can be seen replacing the normal dark brown thyroid tissue.
When examined under a microscope, thyroid nodular hyperplasia consists of abnormal follicles ranging in size from small to very large. As a result of the overgrowth, the thyroid gland divides into small, round nodules.The follicular cells in these abnormal follicles are very similar to the follicular cells of the normal thyroid gland.
Some pathology reports use the word “adenomatoid” to describe the nodes seen in thyroid nodular hyperplasia. Adenomatoid means the nodules looked like a non-cancerous type of growth called follicular adenoma. Unlike follicular adenomas, adenomatoid nodules are not completely surrounded or separated from normal thyroid tissue by a thin layer of tissue called a capsule.The word “dominant” is used to describe the largest adenomatoid node.
A thyroid gland enlarged as a result of nodular hyperplasia of the thyroid gland will show signs of trauma that pathologists describe as degenerative changes. When examined under a microscope, these changes include hemosiderin (old blood), fibrosis (scar), and the development of small open spaces called cysts.
Changes with fine needle aspiration (FNA)
If you had an FNA before thyroid surgery, the pathologist will be able to see the changes caused by the needle when examining the tissue under a microscope. These changes usually include bleeding and scarring in the path of the needle. If your pathologist is unsure if you performed an FNA prior to thyroid removal, he may describe these changes as “FNA-like”.
Pathologists use the term metaplasia to describe a group of cells that have evolved from one specialized type of cell to another. Metaplasia is a non-cancerous change. There are two types of metaplasia that are commonly seen in thyroid nodular hyperplasia.
- Oncocytic metaplasia – Normal follicular cells have increased in size and the cell body appears bright pink. In the thyroid gland, these bright pink cells are also called Hertle cells.
- Squamous Cell Metaplasia – Normal follicular cells have evolved into specialized cells called flat cells that are usually found on the surface of the skin and in the mouth.
Pathologists use the term reactive atypia to describe follicular cells that appear abnormal in shape, size, or color. Reactive atypia can be caused by: inflammation or previous puncture of a fine needle. Reactive atypia is a non-malignant change that is usually associated with nodular hyperplasia of the thyroid gland.
Other names for nodular hyperplasia of the thyroid gland
Other names for nodular thyroid hyperplasia include nodular thyroid disease, nodular follicular disease, and adenomatous hyperplasia. Non-pathologists use the word goiter to describe the changes caused by thyroid nodular hyperplasia.
Jason Wasserman MD, FRCPC (updated September 20, 2021)
In order to talk about diseases of the cardiovascular system, it is necessary to imagine its structure. The circulatory system is divided into arterial and venous. Through the arterial system, blood flows from the heart, through the venous system, it flows to the heart. Distinguish between a large and a small circle of blood circulation.
The great circle includes the aorta (ascending and descending, aortic arch, thoracic and abdominal), through which blood flows from the left heart. From the aorta, blood enters the carotid arteries that supply blood to the brain, subclavian arteries, blood supplying arms, renal arteries, arteries of the stomach, intestines, liver, spleen, pancreas, pelvic organs, iliac and femoral arteries, blood supplying legs. From the internal organs, blood flows through the veins, which flow into the superior vena cava (collects blood from the upper half of the body) and the inferior vena cava (collects blood from the lower half of the body).The hollow veins flow into the right heart.
Lesser circulation includes the pulmonary artery (through which venous blood nevertheless flows). Through the pulmonary artery, blood enters the lungs, where it is enriched with oxygen and becomes arterial. Through the pulmonary veins (four), arterial blood enters the left heart.
Pumps blood heart – a hollow muscular organ, consisting of four sections. It is the right atrium and right ventricle that make up the right heart and the left atrium and left ventricle that make up the left heart.Oxygen-rich blood flowing from the lungs through the pulmonary veins enters the left atrium, from it – into the left ventricle and further into the aorta. Venous blood through the superior and inferior vena cava enters the right atrium, from there into the right ventricle and then through the pulmonary artery into the lungs, where it is enriched with oxygen and again enters the left atrium.
Distinguish between pericardium, myocardium and endocardium. The heart is located in the heart sac – the pericardium. Cardiac muscle – the myocardium consists of several layers of muscle fibers, there are more of them in the ventricles than in the atria.These fibers, by contracting, push blood from the atria to the ventricles and from the ventricles to the vessels. The internal cavities of the heart and valves are lined by the endocardium.
Heart valve apparatus.
Between the left atrium and the left ventricle there is a mitral (bicuspid) valve, between the right atrium and the right ventricle – a tricuspid (tricuspid) valve. The aortic valve is located between the left ventricle and the aorta, the pulmonary valve is between the pulmonary artery and the right ventricle.
The work of the heart.
From the left and right atrium, blood enters the left and right ventricles, while the mitral and tricuspid valves are open, the aortic and pulmonary valves are closed. This phase in the work of the heart is called diastole. Then the mitral and tricuspid valves close, the ventricles contract and through the opened aortic and pulmonary artery valves, blood, respectively, rushes into the aorta and pulmonary artery. This phase is called systole; systole is shorter than diastole.
Conductive system of the heart.
We can say that the heart works autonomously – it itself generates an electrical impulse that spreads through the heart muscle, causing it to contract.The pulse should be generated with a certain frequency – normally about 50-80 pulses per minute. In the conducting system of the heart, a sinus node is distinguished (located in the right atrium), nerve fibers go from it to the atrioventricular (atrioventricular) node (located in the interventricular septum – the wall between the right and left ventricles). From the atrioventricular node, nerve fibers go in large bundles (right and left leg of His), dividing in the walls of the ventricles into smaller ones (Purkinje fibers). An electrical impulse is generated in the sinus node and propagates along the conductive system in the thickness of the myocardium (heart muscle).
Blood supply to the heart.
Like all organs, the heart must receive oxygen. Oxygen is delivered through arteries called coronary arteries. The coronary arteries (right and left) depart from the very beginning of the ascending aorta (at the site of the origin of the aorta from the left ventricle). The trunk of the left coronary artery is divided into the descending artery (aka the anterior interventricular artery) and the envelope.These arteries give off branches – an artery of a blunt edge, diagonal, etc. Sometimes the so-called median artery departs from the trunk. The branches of the left coronary artery supply the anterior wall of the left ventricle, most of the interventricular septum, the lateral wall of the left ventricle, and the left atrium. The right coronary artery supplies a portion of the right ventricle and the posterior wall of the left ventricle.
Now that you have become a specialist in the anatomy of the cardiovascular system, let’s move on to its diseases.
Thyroid pathology | Prof. Mario Bussey Otolaryngologist
Anatomy and Physiology
The thyroid gland is an endocrine gland located in the middle part of the neck, under the larynx, in front of the trachea.
Consists of two symmetrical lobes connected by a narrow isthmus (isthmus), sometimes the remains of the embryonic thyroid-lingual duct are present, which form an additional pyramidal lobe (Lalouette pyramid).Produces iodine-containing hormones thyroxine (tetraiodothyranine, T4) and triiodothyronine (T3). The capture of iodine by the gland occurs through active transfer, which is regulated by TSH (thyroid-stimulating hormone) of the anterior pituitary gland, after which it is inglobed with thyroglobulin. Enzymatic breakdown of thyroglobulin (proteolysis) results in the release of thyroid hormones (T3 and T4) and their entry into the blood. Thyroid hormones are biologically highly active substances that control metabolism and energy, growth processes, maturation of tissues and organs.
Non-malignant pathologies of the thyroid gland.
Such pathologies should be considered by a specialist endocrinologist or may be of surgical interest. Among benign forms of surgical interest, nodular non-malignant pathology and a nodular or diffuse form are distinguished.
Depending on the level of hormone production, each of the forms may be accompanied by hypothyroidism, euthyroidism and hyperthyroidism, i.e. associated with functional impairment, normal function or hyperfunction of the thyroid gland.
Condition due to functional insufficiency of the thyroid gland. The clinical manifestations of hypothyroidism are often scanty, but progressive: lethargy, decreased performance and fatigue, drowsiness, memory loss, a feeling of chilliness, weight gain, and constipation. In some cases, myxedema edema and bradycardia may occur, and the most severe complication is myxedema coma.
Diagnosis is based on clinical studies of the patient, in particular, with hypothyroidism, the level of thyroid hormones decreases with a sharp increase in TSH.Determination of antibodies to thyroglobulin, as well as antibodies to thyroid peroxidase, makes it possible to exclude dysfunction of the thyroid gland on an autoimmune basis.
Characterized by excessive concentration of thyroid hormones. Clinical manifestations are tachycardia, shallow tremors, anxiety, insomnia, heat intolerance, increased appetite, weight loss, diarrhea, menstrual irregularities (up to amenorrhea), skin and hair changes.
Nodular non-malignant pathology
Thyroid nodules are a limited change in the area of the parenchyma of the gland, which is detected by palpation and ultrasound examination.
These neoplasms are widespread in the population and can be solid, fluid, or mixed. They often remain asymptomatic if they do not provoke dysfunctions of the gland or reach especially large sizes.
Among the nodal pathologies, it is necessary to single out adenomas, which, according to their histology, are subdivided into papillary and follicular.
Among the adenomas of the thyroid gland, let us recall Plummer’s disease (Plummer’s syndrome) or toxic adenoma of the thyroid gland – a benign tumor that autonomously produces thyroid hormones, manifests itself as a clinical picture of hyperthyroidism. Clinical data, assessment of the functional state of the thyroid gland and finally instrumental examination (ultrasound and scintigraphy) are a reliable diagnostic criterion. Surgical treatment (thyroidectomy) is carried out with preliminary pharmacological training aimed at correcting hyperthyroidism.
DIFFUSE PATHOLOGY OF STRUM OR GOITER
The most common thyroid pathology is struma or goiter . It appears with an increase in the size of the gland and the most common cause of its occurrence is iodine deficiency.
The disease is typical for women, and in some areas is endemic. Struma is a macroscopically expressed, complete or partial hyperplasia of the thyroid tissue. According to the macromorphological principle, a diffuse goiter, nodular goiter or diffuse multinodular goiter can be distinguished.
In the initial stages, the only symptom is a volumetric enlargement of the gland. In more complex cases, it can be accompanied by a displacement of the trachea and esophagus, thus provoking the appearance of symptoms of respiratory or digestive compression (dysphagia). From the point of view of the functionality of the thyroid gland, struma can provoke euthyroidism, hyper or hypothyroidism.
In most cases, medical treatment, surgery is indicated in the case of goiter with existing signs of compression of surrounding organs and / or a cosmetic defect.
Observed with excessive secretion of thyroid hormones (hyperthyroidism), caused by autoimmune processes in the body. In particular, lymphocytes produce an abnormal protein (immunoglobulin) that stimulates the thyroid gland. The result is a volumetric increase such. The disease is accompanied by thyrogenic ophthalmopathy, which is characterized by exophthalmos (enlargement and protrusion of the eyeball) and periorbital edema.In the initial stages, drug treatment. In the absence of a positive effect, surgical treatment (thyroidectomy) or treatment with radioactive iodine (isotope of iodine 131) is performed. Whereas the problem of the eyeball often requires surgical intervention aimed at returning it to orbit.
Among the inflammatory processes of the thyroid gland Chronic Hashimoto’s thyroiditis and Riedel’s thyroiditis should be noted.
Chronic Thyroiditis Hashimoto autoimmune damage to the gland, leading to an increase in its volume and subsequent progressive evolution of sclerosis of thyroid tissue, and finally to its hyperfunctionality (hyperthyroidism). In the treatment, drugs are used to correct the immune system (immunosuppressive therapy), and to restore functional balance – synthetic thyroid hormones.
Riedel’s thyroiditis differs from the previous one by the growth in the thyroid gland of coarse-fibrous tissue in the form of a dense knot without clear boundaries, leading to adhesions of the trachea and esophagus.
MALIGNANT TUMORS (CANCER) OF THE THYROID GLAND
Malignant tumors of the thyroid gland are in progressive increase, however, the mortality from this disease has not changed quantitatively. Cancer of the thyroid gland is divided into differentiated (papillary and follicular), undifferentiated and medullary. Sarcoma and lymphoma are much less common. Currently, with such a pathology, surgical treatment is used – thyroidectomy.
PAPILLARY THYROID CARCINOMA
Papillary carcinoma is the most common form of thyroid cancer.The neoplasms are usually encapsulated or partially encapsulated; calcified masses or cystic formations with hemorrhagic contents are often found in the tissues of the gland. Depending on the histopathological structure, it is possible to distinguish the follicular form (encapsulated), sclerosing (with wide lymphatic spread), the so-called “tall-cell” form and the form of increased aggression with colonial formations.
Approximately 30% of thyroid cancers involve cervical lymph nodes; nevertheless, in 95% of cases, the tumor is localized and rarely causes distant metastases.
FOLLICULAR THYROID CARCINOMA
It is an epithelial neoplasm with no histological characteristics of papillary carcinoma. This form also includes Gürtle-cell carcinoma with a constituent oncocytic component.
Follicular carcinoma is associated with a chronic lack of iodine in the body and, unlike papillary carcinoma, usually occurs at an older age, rarely forms additional foci in the lymph nodes of the neck (4-6%), but more often it metastases to other structures, such as bones and lungs (5-20%).
MEDULLARY THYROID CARCINOMA
The source of the formation of this carcinoma is the C-cells of the thyroid gland, which normally produce calcitonin, a hormone involved in the regulation of calcium metabolism in the body. With the formation of medullary carcinoma, the level of calcitonin in the blood rises sharply, tumor cells spread through the lymph nodes of the cervical nodes or hematogenously, followed by metastasis to the bones, lungs and liver.
Medullary carcinoma may occur sporadically, but is inherited in 25% of cases as part of the multiple endocrine neoplasia syndrome (MEN).In particular, it is associated with MEN 2A and MEN 2B.
SANAPLASTIC THYROID CARCINOMA
It makes up about 5% of all malignant thyroid neoplasms, occurs after the sixth decade of life.
Anaplastic cancer is an extremely aggressive carcinoma characterized by rapid growth with invasion of surrounding organs and tissues, as well as metastasis.
Reliable diagnosis of thyroid pathology requires close cooperation of various specialists (otolaryngologists, endocrinologists, ultrasound echography specialists, anatomical pathologists).Diagnostics includes studies of 1 and 2 degrees.
BLOOD BIOCHEMICAL ANALYSIS
For general diagnostics, studies of the levels of thyroid-stimulating hormone TSH , hormones T4 and T3 , as well as free fractions of thyroid hormones pT3 , pT4 are carried out.
Blood calcitonin levels should be tested if medullary carcinoma is suspected.
Determination of antibodies to thyroglobulin (AT-TG) , as well as antibodies to thyroid peroxidase (AT-TPO) , is used in the diagnosis of autoimmune pathologies of the thyroid gland.
Indicators such as parathyroid hormone (PTH), calcium and phosphorus levels in the blood indicate thyropathy.
INSTRUMENTAL RESEARCH Ultrasound (US)
A non-invasive and easy-to-perform method that allows you to assess the size, location and symmetry of the gland lobes, the size and structure of the nodular formation, the state of the regional lymph nodes.
Doppler ultrasound detects the degree of vascularization of the gland or possible neoplasms, thus making it possible to assess their malignancy.
Computed tomography (CT) and magnetic resonance imaging (MPT)
These studies are carried out with neoplasms or goiter, in order to determine the size of the thyroid gland in relation to other nearby organs.
It should be recalled that if neoplastic pathology is suspected, isotope scanning should be avoided due to possible radioiodine therapy.
Allows to divide the nodal neoplasms into the so-called hot and cold nodules.
During scytigraphy, hot nodules are hyperfunctioning, representing 5% of all thyroid nodules, and negative degeneration of these is practically not found. Cold nodules represent a higher chance of malignancy (about 10%).
Fibrolaryngoscopy of the larynx
Is the most reliable method for examining the larynx and assessing the mobility of the vocal cords. Such findings help in the study of malignant thyroid tumors, which can infiltrate the nerve that controls the movement of the vocal cords.
Such examination is mandatory during planning of surgical treatment in order to prevent possible iatrogenic nerve damage.
If a nodular formation is detected, a fine-needle targeted aspiration biopsy (TPAB) is performed under ultrasound guidance. TPAP is the most accurate diagnostic method and is performed in the presence of nodules with a diameter of more than 1 cm.In the case of nodules with a diameter of less than 1 cm, they should have signs indicating possible malignancy, occur in patients with possible hereditary carcinoma or have been exposed to radiation …
Any malignant thyroid pathology (cancer), established or suspected, requires surgical treatment. Also, many other diseases of the thyroid gland may require surgical treatment. It is preferable that the issue of surgical intervention is decided jointly by a surgeon and an endocrinologist. When focusing on surgery, the patient should be informed about the characteristics, benefits and consequences of such.
The following categories of patients are subject to possible surgical intervention:
- patients with fast-growing nodules
- patients with cervical-medial goiter
- patients with thyrotoxic adenoma (Plummer’s adenoma)
- patients with a cosmetic defect provoked by the size of the strum
90,073 patients in whom an enlarged thyroid gland causes difficulty breathing or swallowing.
90,073 patients with toxic goiter, i.e. with thyroid hyperfunction
Patients with an established diagnosis of thyroid cancer are subject to compulsory surgery.Regional lymph nodes may be removed during surgery to achieve optimal results in the treatment of these neoplasms, depending on their histology and the presence of suspected lymph nodes. Less commonly, in advanced-stage cancers, surgical treatment may involve nearby anatomical structures. Such drastic decisions are predictable on the basis of preoperative studies (stage of the disease), and are usually discussed with the patient before hospitalization.
Currently, possible surgical alternatives are total thyroidectomy or subtotal thyroidectomy (hemithyroidectomy) .
In these cases, the operation involves a small horizontal incision in the neck. The use of a fiber optic endoscope, commonly used in otorhinolaryngology, can significantly reduce the incision length. This so-called minimally invasive technique, which in surgery is called MIVAT , is a minimally invasive video-assisted thyroidectomy.The choice of this method of treatment (which, however, does not modify the amount of tissue removed) is discussed between the patient and the surgeon in a personal conversation before the operation. In any case, surgical treatment includes the following components: identification and preservation of the recurrent laryngeal nerve and parathyroid glands (regulate calcium metabolism in the body), removal of either the entire gland or one of its lobes, the establishment of drainage tubes and the imposition of hidden sutures, giving a high cosmetic result.
The identification and preservation of the laryngeal nerves and parathyroid glands requires a great deal of experience and high level of skill from the surgeon. It should be recalled that damage to the laryngeal nerve leads to unilateral paralysis of the larynx, where voice impairment comes to the fore. With bilateral paresis of the larynx, the vital functions of the larynx – respiratory and dividing functions are also disturbed, as a result of which a tracheotomy may be necessary (the risk level is very low).
Preservation of the parathyroid glands is necessary to maintain the exchange of calcium in the body.In the postoperative period, the patient is monitored for calcium to ensure the correct function of the preserved parathyroid glands. In some cases, despite the preservation of the parathyroid glands, there is a state of postoperative hypocalcemia, characteristic of ischemic damage during the operation. In these cases, calcium restorative treatment is carried out until the parathyroid glands restore their function.