Adenocarcinoma, Follicular
Thyroid Gland
Carcinoma, Papillary
Thyroid Nodule
Biopsy, Fine-Needle
Carcinoma
Adenoma, Oxyphilic
Galectin 3
Thyroid Hormones
Tumor Markers, Biological
Immunohistochemistry
Receptors, Thyroid Hormone
Thyrotropin
Triiodothyronine
Thyroxine
Hypothyroidism
Thyroglobulin
Pancreatic Neoplasms
Iodide Peroxidase
Thyroid Hormone Receptors beta
Neoplasms
Goiter
Hyperthyroidism
Iodine
Neoplasms, Cystic, Mucinous, and Serous
Thyroiditis, Autoimmune
Thyroid Hormone Receptors alpha
Graves Disease
Neoplasms, Multiple Primary
Adenocarcinoma, Papillary
Iodine Radioisotopes
Carcinoma, Papillary, Follicular
Goiter, Nodular
Carcinoma, Medullary
Over-representation of a germline RET sequence variant in patients with sporadic medullary thyroid carcinoma and somatic RET codon 918 mutation. (1/4130)
The aetiology of sporadic medullary thyroid carcinoma is unknown. About 50% harbour a somatic mutation at codon 918 of RET (M918T). To investigate whether other RET sequence variants may be associated with or predispose to the development of sporadic medullary thyroid carcinoma, we analysed genomic DNA from the germline and corresponding tumour from 50 patients to identify RET sequence variants. In one patient, tumour DNA showed a novel somatic 12 bp in-frame deletion in exon 15. More interestingly, we found that the rare polymorphism at codon 836 (c.2439C > T; S836S) occurred at a significantly higher frequency than that in control individuals without sporadic medullary thyroid carcinoma (Fisher's exact test, P = 0.03). Further, among the nine evaluable cases with germline c.2439C/T, eight also had the somatic M918T mutation in MTC DNA which was more frequent than in patients with the more common c.2439C/C (89% vs 40%, respectively; Fisher's exact test, P = 0.01). These findings suggest that the rare sequence variant at codon 836 may somehow play a role in the genesis of sporadic medullary thyroid carcinoma. (+info)Medullary thyroid carcinoma with multiple hepatic metastases: treatment with transcatheter arterial embolization and percutaneous ethanol injection. (2/4130)
A 54-year-old man with medullary thyroid carcinoma in the thyroid gland was unable to undergo total thyroidectomy because the tumor had invaded the mediastinum. Radiation therapy and chemotherapy were given. Seven years later, intractable diarrhea and abdominal pain appeared, and computed tomography demonstrated hypervascular tumors in the thyroid gland and in the liver. The tumors were successfully treated with percutaneous ethanol injection to a lesion in the thyroid gland and transcatheter arterial embolization followed by percutaneous ethanol injection to tumors in the liver. Transcatheter arterial embolization and percutaneous ethanol injection may be valuable in treating medullary thyroid carcinoma. (+info)Epithelial thyroid tumors in cows. (3/4130)
From 1964 to 1973, 370 tumors were collected from cows of unknown age. Ten (2.7%) of these were primary thyroid tumors. Three were malignant. The benign tumors were solitary encapsulated adenomas in the parenchyma with more or less defined trabeculae, tubular, and microfollicular pattern. One of the malignant tumors was a cystic papillary adenocarcinoma, and two were small cell carcinomas consisting of small, sometimes binuclear, pleomorphic cells. (+info)Overexpression of fibroblast growth factor receptor 3 in a human thyroid carcinoma cell line results in overgrowth of the confluent cultures. (4/4130)
Recent reports indicate that a gain-of-function mutation in fibroblast growth factor receptor 3 (FGFR-3) inhibits cell growth in the cartilaginous growth plates. These results suggest that FGFR-3 may be the receptor transducing growth inhibitory signals. Using reverse transcription-PCR we examined seven papillary thyroid carcinomas to determine FGFR-3 expression. Six out of the seven papillary carcinomas expressed FGFR-3. To clarify the role of FGFR-3 in thyroid carcinoma, FGFR-3 was overexpressed in an established human papillary thyroid carcinoma cell line. High levels of FGFR-3 protein were identified in cells stably transfected with the vector containing FGFR-3 cDNA. The specific binding of 125I-FGF-2 of these cells was threefold higher than that of control cells. Growth rates of cells overexpressing FGFR-3 were similar to those of control cells. However, cells overexpressing FGFR-3 continued to grow beyond the density at which control cells stopped proliferating. These results suggest that FGFR-3 in thyroid carcinoma is not involved strongly in the cell proliferation mechanism but may contribute to the malignant extension of some of the carcinomas by modifying cell contact signaling. (+info)Psychosocial impact of genetic testing in familial medullary-thyroid carcinoma: a multicentric pilot-evaluation. (5/4130)
BACKGROUND: Many crucial problems are associated with the diagnosis of inherited cancer susceptibility. One of the most important is related to the psychosocial consequences of the knowledge by the patients and their relatives of their own genetical status. Little data are available in the literature, mainly from studies including small numbers of selected and motivated patients. PATIENTS AND METHODS: From January till December 1997, we studied the psychometric and quality of life parameters of 77 subjects followed in two French specialized centers. These subjects had been treated for either sporadic or familial or were at risk for medullary thyroid carcinoma. All patients had previously attended genetic counselling with detection of germline Ret-mutations, were informed on their own genetic risk, had good short-term prognosis and performance status and did not receive recent cancer treatment. Each patient was invited to answer two questionnaires, the hospital anxiety and depression scale (HADS) and the subjective quality of life profile (SQLP). RESULTS: We report herein the descriptive results of this study (HADS and SQLP scores and distributions) and describe the individual clinical covariates that might explain the observed differences between subgroups of individuals. Although psychometric scores appeared similar in these subgroups, quality of life scores were lower in Ret-mutation carriers. Genetically-predisposed patients were less satisfied and expressed more expectations for favourable change in their quality of life. CONCLUSION: This finding suggests a high level of frustration and latent unsatisfaction related either to the management of the genetic information given by the clinicians and its psychosocial consequences or simply to the knowledge of the genetic risk of cancer. Further studies on the individual consequences of genetic testing, information delivery and when necessary psychotherapeutic interventions, are needed to insure the quality of presymptomatic genetic testing in this field of oncology. (+info)A new rapid technique for the fixation of thyroid gland surgical specimens. (6/4130)
One of the main diagnostic problems in thyroid pathology is to distinguish between follicular adenoma and follicular carcinoma. Thorough sampling of the nodule's capsule is recommended in order to identify capsular invasion. However, during the hardening of the tissue, by the usual fixatives the capsule shrinks and rolls downwards and sometimes the capsule separates from the remaining tissue. The present work evaluates the use of "Lymph Node Revealing Solution" (LNRS) for the rapid fixation (2h) of different thyroid lesions as compared to that of formalin. Fifty-one unselected consecutive cases of thyroid nodules, which included various benign and malignant lesions, were examined. Each specimen was cut in two equal parts; one was fixed in LNRS, the other in formalin. Fixation in LNRS for 2 hours gave adequate results in sectioning and staining of the tissue, and excellent immunostains. Its advantage over formalin is the conservation of the natural relationship between the capsule and the rest of the tissue, on the same plane, as well as the short time required for the final diagnosis. (+info)Overexpression of c-Ras in hyperplasia and adenomas of the feline thyroid gland: an immunohistochemical analysis of 34 cases. (7/4130)
Formalin-fixed, paraffin-embedded thyroid glands from 18 cats diagnosed with hyperthyroidism were evaluated immunohistochemically for overexpression of the products of oncogenes c-ras and bcl2 and the tumor suppressor gene p53. Fourteen thyroid glands from euthyroid cats without histologically detectable thyroid lesions were examined similarly as controls. Results from these investigations showed that all cases of nodular follicular hyperplasia/adenomas stained positively for overexpression of c-Ras protein using a mouse monoclonal anti-human pan-Ras antibody. The most intensely positively staining regions were in luminal cells surrounding abortive follicles. Subjacent thyroid and parathyroid glands from euthyroid cats did not stain immunohistochemically for pan-Ras. There was no detectable staining for either Bc12 or p53 in any of the cats. These results indicated that overexpression of c-ras was highly associated with areas of nodular follicular hyperplasia/adenomas of feline thyroid glands, and mutations in this oncogene may play a role in the etiopathogenesis of hyperthyroidism in cats. (+info)Human thyroid cancer cells as a source of iso-genic, iso-phenotypic cell lines with or without functional p53. (8/4130)
Differentiated thyroid carcinomas (in contrast to the rarer anaplastic form) are unusual among human cancers in displaying a remarkably low frequency of p53 mutation and appear to retain wild-type (wt) p53 function as assessed by the response of derived cell lines to DNA damage. Using one such cell line, K1, we have tested the effect of experimental abrogation of p53 function by generating matched sub-clones stably expressing either a neo control gene, a dominant-negative mutant p53 (143ala) or human papilloma virus protein HPV16 E6. Loss of p53 function in the latter two groups was confirmed by abolition of p53-dependent 'stress' responses including induction of the cyclin/CDK inhibitor p21WAF1 and G1/S arrest following DNA-damage. In contrast, no change was detected in the phenotype of 'unstressed' clones, with respect to any of the following parameters: proliferation rate in monolayer, serum-dependence for proliferation or survival, tumorigenicity, cellular morphology, or tissue-specific differentiation markers. The K1 line therefore represents a 'neutral' background with respect to p53 function, permitting the derivation of functionally p53 + or - clones which are not only iso-genic but also iso-phenotypic. Such a panel should be an ideal tool with which to test the p53-dependence of cellular stress responses, particularly the sensitivity to potential therapeutic agents, free from the confounding additional phenotypic differences which usually accompany loss of p53 function. The results also further support the hypothesis that p53 mutation alone is not sufficient to drive progression of thyroid cancer to the aggressive anaplastic form. (+info)Thyroid neoplasms refer to abnormal growths or tumors in the thyroid gland, which can be benign (non-cancerous) or malignant (cancerous). These growths can vary in size and may cause a noticeable lump or nodule in the neck. Thyroid neoplasms can also affect the function of the thyroid gland, leading to hormonal imbalances and related symptoms. The exact causes of thyroid neoplasms are not fully understood, but risk factors include radiation exposure, family history, and certain genetic conditions. It is important to note that most thyroid nodules are benign, but a proper medical evaluation is necessary to determine the nature of the growth and develop an appropriate treatment plan.
Adenocarcinoma, follicular is a type of cancer that develops in the follicular cells of the thyroid gland. The thyroid gland is a butterfly-shaped endocrine gland located in the neck that produces hormones responsible for regulating various bodily functions such as metabolism and growth.
Follicular adenocarcinoma arises from the follicular cells, which are responsible for producing thyroid hormones. This type of cancer is typically slow-growing and may not cause any symptoms in its early stages. However, as it progresses, it can lead to a variety of symptoms such as a lump or nodule in the neck, difficulty swallowing, hoarseness, or pain in the neck or throat.
Follicular adenocarcinoma is usually treated with surgical removal of the thyroid gland (thyroidectomy), followed by radioactive iodine therapy to destroy any remaining cancer cells. In some cases, additional treatments such as radiation therapy or chemotherapy may be necessary. The prognosis for follicular adenocarcinoma is generally good, with a five-year survival rate of around 90%. However, this can vary depending on the stage and aggressiveness of the cancer at the time of diagnosis.
The thyroid gland is a major endocrine gland located in the neck, anterior to the trachea and extends from the lower third of the Adams apple to the suprasternal notch. It has two lateral lobes, connected by an isthmus, and sometimes a pyramidal lobe. This gland plays a crucial role in the metabolism, growth, and development of the human body through the production of thyroid hormones (triiodothyronine/T3 and thyroxine/T4) and calcitonin. The thyroid hormones regulate body temperature, heart rate, and the production of protein, while calcitonin helps in controlling calcium levels in the blood. The function of the thyroid gland is controlled by the hypothalamus and pituitary gland through the thyroid-stimulating hormone (TSH).
Carcinoma, papillary is a type of cancer that begins in the cells that line the glandular structures or the lining of organs. In a papillary carcinoma, the cancerous cells grow and form small finger-like projections, called papillae, within the tumor. This type of cancer most commonly occurs in the thyroid gland, but can also be found in other organs such as the lung, breast, and kidney. Papillary carcinoma of the thyroid gland is usually slow-growing and has a good prognosis, especially when it is diagnosed at an early stage.
An adenoma is a benign (noncancerous) tumor that develops from glandular epithelial cells. These types of cells are responsible for producing and releasing fluids, such as hormones or digestive enzymes, into the surrounding tissues. Adenomas can occur in various organs and glands throughout the body, including the thyroid, pituitary, adrenal, and digestive systems.
Depending on their location, adenomas may cause different symptoms or remain asymptomatic. Some common examples of adenomas include:
1. Colorectal adenoma (also known as a polyp): These growths occur in the lining of the colon or rectum and can develop into colorectal cancer if left untreated. Regular screenings, such as colonoscopies, are essential for early detection and removal of these polyps.
2. Thyroid adenoma: This type of adenoma affects the thyroid gland and may result in an overproduction or underproduction of hormones, leading to conditions like hyperthyroidism (overactive thyroid) or hypothyroidism (underactive thyroid).
3. Pituitary adenoma: These growths occur in the pituitary gland, which is located at the base of the brain and controls various hormonal functions. Depending on their size and location, pituitary adenomas can cause vision problems, headaches, or hormonal imbalances that affect growth, reproduction, and metabolism.
4. Liver adenoma: These rare benign tumors develop in the liver and may not cause any symptoms unless they become large enough to press on surrounding organs or structures. In some cases, liver adenomas can rupture and cause internal bleeding.
5. Adrenal adenoma: These growths occur in the adrenal glands, which are located above the kidneys and produce hormones that regulate stress responses, metabolism, and blood pressure. Most adrenal adenomas are nonfunctioning, meaning they do not secrete excess hormones. However, functioning adrenal adenomas can lead to conditions like Cushing's syndrome or Conn's syndrome, depending on the type of hormone being overproduced.
It is essential to monitor and manage benign tumors like adenomas to prevent potential complications, such as rupture, bleeding, or hormonal imbalances. Treatment options may include surveillance with imaging studies, medication to manage hormonal issues, or surgical removal of the tumor in certain cases.
A thyroid nodule is a growth or lump that forms within the thyroid gland, a small butterfly-shaped endocrine gland located in the front of your neck. Thyroid nodules can be solid or fluid-filled (cystic) and vary in size. Most thyroid nodules are benign (noncancerous) and do not cause symptoms. However, some thyroid nodules may be cancerous or overproduce hormones, leading to hyperthyroidism. The exact cause of thyroid nodules is not always known, but factors such as iodine deficiency, Hashimoto's disease, and family history can increase the risk of developing them. A healthcare professional typically diagnoses a thyroid nodule through physical examination, imaging tests like ultrasound, or fine-needle aspiration biopsy to determine if further treatment is necessary.
A fine-needle biopsy (FNB) is a medical procedure in which a thin, hollow needle is used to obtain a sample of cells or tissue from a suspicious or abnormal area in the body, such as a lump or mass. The needle is typically smaller than that used in a core needle biopsy, and it is guided into place using imaging techniques such as ultrasound, CT scan, or MRI.
The sample obtained during an FNB can be used to diagnose various medical conditions, including cancer, infection, or inflammation. The procedure is generally considered safe and well-tolerated, with minimal risks of complications such as bleeding, infection, or discomfort. However, the accuracy of the diagnosis depends on the skill and experience of the healthcare provider performing the biopsy, as well as the adequacy of the sample obtained.
Overall, FNB is a valuable diagnostic tool that can help healthcare providers make informed decisions about treatment options and improve patient outcomes.
Carcinoma is a type of cancer that develops from epithelial cells, which are the cells that line the inner and outer surfaces of the body. These cells cover organs, glands, and other structures within the body. Carcinomas can occur in various parts of the body, including the skin, lungs, breasts, prostate, colon, and pancreas. They are often characterized by the uncontrolled growth and division of abnormal cells that can invade surrounding tissues and spread to other parts of the body through a process called metastasis. Carcinomas can be further classified based on their appearance under a microscope, such as adenocarcinoma, squamous cell carcinoma, and basal cell carcinoma.
An oxyphilic adenoma is a type of benign tumor that develops in the endocrine glands, specifically in the parathyroid gland. This type of adenoma is characterized by the presence of cells called oxyphils, which have an abundance of mitochondria and appear pink on histological examination due to their high oxidative enzyme activity. Oxyphilic adenomas are a common cause of primary hyperparathyroidism, a condition in which the parathyroid glands produce too much parathyroid hormone (PTH), leading to an imbalance of calcium and phosphorus metabolism. Symptoms of primary hyperparathyroidism may include fatigue, weakness, bone pain, kidney stones, and psychological disturbances. Treatment typically involves surgical removal of the affected parathyroid gland.
Galectin-3 is a type of protein belonging to the galectin family, which binds to carbohydrates (sugars) and plays a role in various biological processes such as inflammation, immune response, and cancer. It is also known as Mac-2 binding protein or LGALS3.
Galectin-3 is unique among galectins because it can form oligomers (complexes of multiple subunits) and has a wide range of functions in the body. It is involved in cell adhesion, proliferation, differentiation, apoptosis (programmed cell death), and angiogenesis (formation of new blood vessels).
In the context of disease, Galectin-3 has been implicated in several pathological conditions such as fibrosis, heart failure, and cancer. High levels of Galectin-3 have been associated with poor prognosis in patients with heart failure, and it is considered a potential biomarker for this condition. In addition, Galectin-3 has been shown to promote tumor growth, angiogenesis, and metastasis, making it a target for cancer therapy.
Thyroid hormones are hormones produced and released by the thyroid gland, a small endocrine gland located in the neck that helps regulate metabolism, growth, and development in the human body. The two main thyroid hormones are triiodothyronine (T3) and thyroxine (T4), which contain iodine atoms. These hormones play a crucial role in various bodily functions, including heart rate, body temperature, digestion, and brain development. They help regulate the rate at which your body uses energy, affects how sensitive your body is to other hormones, and plays a vital role in the development and differentiation of all cells of the human body. Thyroid hormone levels are regulated by the hypothalamus and pituitary gland through a feedback mechanism that helps maintain proper balance.
Thyroid diseases are a group of conditions that affect the function and structure of the thyroid gland, a small butterfly-shaped endocrine gland located in the base of the neck. The thyroid gland produces hormones that regulate many vital functions in the body, including metabolism, growth, and development.
Thyroid diseases can be classified into two main categories: hypothyroidism and hyperthyroidism. Hypothyroidism occurs when the thyroid gland does not produce enough hormones, leading to symptoms such as fatigue, weight gain, cold intolerance, constipation, and depression. Hyperthyroidism, on the other hand, occurs when the thyroid gland produces too much hormone, resulting in symptoms such as weight loss, heat intolerance, rapid heart rate, tremors, and anxiety.
Other common thyroid diseases include:
1. Goiter: an enlargement of the thyroid gland that can be caused by iodine deficiency or autoimmune disorders.
2. Thyroid nodules: abnormal growths on the thyroid gland that can be benign or malignant.
3. Thyroid cancer: a malignant tumor of the thyroid gland that requires medical treatment.
4. Hashimoto's disease: an autoimmune disorder that causes chronic inflammation of the thyroid gland, leading to hypothyroidism.
5. Graves' disease: an autoimmune disorder that causes hyperthyroidism and can also lead to eye problems and skin changes.
Thyroid diseases are diagnosed through a combination of physical examination, medical history, blood tests, and imaging studies such as ultrasound or CT scan. Treatment options depend on the specific type and severity of the disease and may include medication, surgery, or radioactive iodine therapy.
Thyroidectomy is a surgical procedure where all or part of the thyroid gland is removed. The thyroid gland is a butterfly-shaped endocrine gland located in the neck, responsible for producing hormones that regulate metabolism, growth, and development.
There are different types of thyroidectomy procedures, including:
1. Total thyroidectomy: Removal of the entire thyroid gland.
2. Partial (or subtotal) thyroidectomy: Removal of a portion of the thyroid gland.
3. Hemithyroidectomy: Removal of one lobe of the thyroid gland, often performed to treat benign solitary nodules or differentiated thyroid cancer.
Thyroidectomy may be recommended for various reasons, such as treating thyroid nodules, goiter, hyperthyroidism (overactive thyroid), or thyroid cancer. Potential risks and complications of the procedure include bleeding, infection, damage to nearby structures like the parathyroid glands and recurrent laryngeal nerve, and hypoparathyroidism or hypothyroidism due to removal of or damage to the parathyroid glands or thyroid gland, respectively. Close postoperative monitoring and management are essential to minimize these risks and ensure optimal patient outcomes.
Tumor markers are substances that can be found in the body and their presence can indicate the presence of certain types of cancer or other conditions. Biological tumor markers refer to those substances that are produced by cancer cells or by other cells in response to cancer or certain benign (non-cancerous) conditions. These markers can be found in various bodily fluids such as blood, urine, or tissue samples.
Examples of biological tumor markers include:
1. Proteins: Some tumor markers are proteins that are produced by cancer cells or by other cells in response to the presence of cancer. For example, prostate-specific antigen (PSA) is a protein produced by normal prostate cells and in higher amounts by prostate cancer cells.
2. Genetic material: Tumor markers can also include genetic material such as DNA, RNA, or microRNA that are shed by cancer cells into bodily fluids. For example, circulating tumor DNA (ctDNA) is genetic material from cancer cells that can be found in the bloodstream.
3. Metabolites: Tumor markers can also include metabolic products produced by cancer cells or by other cells in response to cancer. For example, lactate dehydrogenase (LDH) is an enzyme that is released into the bloodstream when cancer cells break down glucose for energy.
It's important to note that tumor markers are not specific to cancer and can be elevated in non-cancerous conditions as well. Therefore, they should not be used alone to diagnose cancer but rather as a tool in conjunction with other diagnostic tests and clinical evaluations.
Immunohistochemistry (IHC) is a technique used in pathology and laboratory medicine to identify specific proteins or antigens in tissue sections. It combines the principles of immunology and histology to detect the presence and location of these target molecules within cells and tissues. This technique utilizes antibodies that are specific to the protein or antigen of interest, which are then tagged with a detection system such as a chromogen or fluorophore. The stained tissue sections can be examined under a microscope, allowing for the visualization and analysis of the distribution and expression patterns of the target molecule in the context of the tissue architecture. Immunohistochemistry is widely used in diagnostic pathology to help identify various diseases, including cancer, infectious diseases, and immune-mediated disorders.
Thyroid function tests (TFTs) are a group of blood tests that assess the functioning of the thyroid gland, which is a small butterfly-shaped gland located in the front of the neck. The thyroid gland produces hormones that regulate metabolism, growth, and development in the body.
TFTs typically include the following tests:
1. Thyroid-stimulating hormone (TSH) test: This test measures the level of TSH, a hormone produced by the pituitary gland that regulates the production of thyroid hormones. High levels of TSH may indicate an underactive thyroid gland (hypothyroidism), while low levels may indicate an overactive thyroid gland (hyperthyroidism).
2. Thyroxine (T4) test: This test measures the level of T4, a hormone produced by the thyroid gland. High levels of T4 may indicate hyperthyroidism, while low levels may indicate hypothyroidism.
3. Triiodothyronine (T3) test: This test measures the level of T3, another hormone produced by the thyroid gland. High levels of T3 may indicate hyperthyroidism, while low levels may indicate hypothyroidism.
4. Thyroid peroxidase antibody (TPOAb) test: This test measures the level of TPOAb, an antibody that attacks the thyroid gland and can cause hypothyroidism.
5. Thyroglobulin (Tg) test: This test measures the level of Tg, a protein produced by the thyroid gland. It is used to monitor the treatment of thyroid cancer.
These tests help diagnose and manage various thyroid disorders, including hypothyroidism, hyperthyroidism, thyroiditis, and thyroid cancer.
Thyroid hormone receptors (THRs) are nuclear receptor proteins that bind to thyroid hormones, triiodothyronine (T3) and thyroxine (T4), and regulate gene transcription in target cells. These receptors play a crucial role in the development, growth, and metabolism of an organism by mediating the actions of thyroid hormones. THRs are encoded by genes THRA and THRB, which give rise to two major isoforms: TRα1 and TRβ1. Additionally, alternative splicing results in other isoforms with distinct tissue distributions and functions. THRs function as heterodimers with retinoid X receptors (RXRs) and bind to thyroid hormone response elements (TREs) in the regulatory regions of target genes. The binding of T3 or T4 to THRs triggers a conformational change, which leads to recruitment of coactivators or corepressors, ultimately resulting in activation or repression of gene transcription.
Thyrotropin, also known as thyroid-stimulating hormone (TSH), is a hormone secreted by the anterior pituitary gland. Its primary function is to regulate the production and release of thyroxine (T4) and triiodothyronine (T3) hormones from the thyroid gland. Thyrotropin binds to receptors on the surface of thyroid follicular cells, stimulating the uptake of iodide and the synthesis and release of T4 and T3. The secretion of thyrotropin is controlled by the hypothalamic-pituitary-thyroid axis: thyrotropin-releasing hormone (TRH) from the hypothalamus stimulates the release of thyrotropin, while T3 and T4 inhibit its release through a negative feedback mechanism.
Triiodothyronine (T3) is a thyroid hormone, specifically the active form of thyroid hormone, that plays a critical role in the regulation of metabolism, growth, and development in the human body. It is produced by the thyroid gland through the iodination and coupling of the amino acid tyrosine with three atoms of iodine. T3 is more potent than its precursor, thyroxine (T4), which has four iodine atoms, as T3 binds more strongly to thyroid hormone receptors and accelerates metabolic processes at the cellular level.
In circulation, about 80% of T3 is bound to plasma proteins, while the remaining 20% is unbound or free, allowing it to enter cells and exert its biological effects. The primary functions of T3 include increasing the rate of metabolic reactions, promoting protein synthesis, enhancing sensitivity to catecholamines (e.g., adrenaline), and supporting normal brain development during fetal growth and early infancy. Imbalances in T3 levels can lead to various medical conditions, such as hypothyroidism or hyperthyroidism, which may require clinical intervention and management.
Thyroxine (T4) is a type of hormone produced and released by the thyroid gland, a small butterfly-shaped endocrine gland located in the front of your neck. It is one of two major hormones produced by the thyroid gland, with the other being triiodothyronine (T3).
Thyroxine plays a crucial role in regulating various metabolic processes in the body, including growth, development, and energy expenditure. Specifically, T4 helps to control the rate at which your body burns calories for energy, regulates protein, fat, and carbohydrate metabolism, and influences the body's sensitivity to other hormones.
T4 is produced by combining iodine and tyrosine, an amino acid found in many foods. Once produced, T4 circulates in the bloodstream and gets converted into its active form, T3, in various tissues throughout the body. Thyroxine has a longer half-life than T3, which means it remains active in the body for a more extended period.
Abnormal levels of thyroxine can lead to various medical conditions, such as hypothyroidism (underactive thyroid) or hyperthyroidism (overactive thyroid). These conditions can cause a range of symptoms, including weight gain or loss, fatigue, mood changes, and changes in heart rate and blood pressure.
Hypothyroidism is a medical condition where the thyroid gland, which is a small butterfly-shaped gland located in the front of your neck, does not produce enough thyroid hormones. This results in a slowing down of the body's metabolic processes, leading to various symptoms such as fatigue, weight gain, constipation, cold intolerance, dry skin, hair loss, muscle weakness, and depression.
The two main thyroid hormones produced by the thyroid gland are triiodothyronine (T3) and thyroxine (T4). These hormones play crucial roles in regulating various bodily functions, including heart rate, body temperature, and energy levels. In hypothyroidism, the production of these hormones is insufficient, leading to a range of symptoms that can affect multiple organ systems.
Hypothyroidism can be caused by several factors, including autoimmune disorders (such as Hashimoto's thyroiditis), surgical removal of the thyroid gland, radiation therapy for neck cancer, certain medications, and congenital defects. Hypothyroidism is typically diagnosed through blood tests that measure levels of TSH (thyroid-stimulating hormone), T3, and T4. Treatment usually involves taking synthetic thyroid hormones to replace the missing hormones and alleviate symptoms.
Thyroglobulin is a protein produced and used by the thyroid gland in the production of thyroid hormones, primarily thyroxine (T4) and triiodothyronine (T3). It is composed of two subunits, an alpha and a beta or gamma unit, which bind iodine atoms necessary for the synthesis of the thyroid hormones. Thyroglobulin is exclusively produced by the follicular cells of the thyroid gland.
In clinical practice, measuring thyroglobulin levels in the blood can be useful as a tumor marker for monitoring treatment and detecting recurrence of thyroid cancer, particularly in patients with differentiated thyroid cancer (papillary or follicular) who have had their thyroid gland removed. However, it is important to note that thyroglobulin is not specific to thyroid tissue and can be produced by some non-thyroidal cells under certain conditions, which may lead to false positive results in some cases.
Pancreatic neoplasms refer to abnormal growths in the pancreas that can be benign or malignant. The pancreas is a gland located behind the stomach that produces hormones and digestive enzymes. Pancreatic neoplasms can interfere with the normal functioning of the pancreas, leading to various health complications.
Benign pancreatic neoplasms are non-cancerous growths that do not spread to other parts of the body. They are usually removed through surgery to prevent any potential complications, such as blocking the bile duct or causing pain.
Malignant pancreatic neoplasms, also known as pancreatic cancer, are cancerous growths that can invade and destroy surrounding tissues and organs. They can also spread (metastasize) to other parts of the body, such as the liver, lungs, or bones. Pancreatic cancer is often aggressive and difficult to treat, with a poor prognosis.
There are several types of pancreatic neoplasms, including adenocarcinomas, neuroendocrine tumors, solid pseudopapillary neoplasms, and cystic neoplasms. The specific type of neoplasm is determined through various diagnostic tests, such as imaging studies, biopsies, and blood tests. Treatment options depend on the type, stage, and location of the neoplasm, as well as the patient's overall health and preferences.
Iodide peroxidase, also known as iodide:hydrogen peroxide oxidoreductase, is an enzyme that belongs to the family of oxidoreductases. Specifically, it is a peroxidase that uses iodide as its physiological reducing substrate. This enzyme catalyzes the oxidation of iodide by hydrogen peroxide to produce iodine, which plays a crucial role in thyroid hormone biosynthesis.
The systematic name for this enzyme is iodide:hydrogen-peroxide oxidoreductase (iodinating). It is most commonly found in the thyroid gland, where it helps to produce and regulate thyroid hormones by facilitating the iodination of tyrosine residues on thyroglobulin, a protein produced by the thyroid gland.
Iodide peroxidase requires a heme cofactor for its enzymatic activity, which is responsible for the oxidation-reduction reactions it catalyzes. The enzyme's ability to iodinate tyrosine residues on thyroglobulin is essential for the production of triiodothyronine (T3) and thyroxine (T4), two critical hormones that regulate metabolism, growth, and development in mammals.
Thyroid hormone receptors (THRs) are nuclear receptor proteins that bind to thyroid hormones and mediate their effects in target cells. There are two main types of THRs, referred to as THR alpha and THR beta. THR beta is further divided into two subtypes, THR beta1 and THR beta2.
THR beta is a type of nuclear receptor that is primarily expressed in the liver, kidney, and heart, as well as in the central nervous system. It plays an important role in regulating the metabolism of carbohydrates, lipids, and proteins, as well as in the development and function of the heart. THR beta is also involved in the regulation of body weight and energy expenditure.
THR beta1 is the predominant subtype expressed in the liver and is responsible for many of the metabolic effects of thyroid hormones in this organ. THR beta2, on the other hand, is primarily expressed in the heart and plays a role in regulating cardiac function.
Abnormalities in THR beta function can lead to various diseases, including thyroid hormone resistance, a condition in which the body's cells are unable to respond properly to thyroid hormones. This can result in symptoms such as weight gain, fatigue, and cold intolerance.
Neoplasms are abnormal growths of cells or tissues in the body that serve no physiological function. They can be benign (non-cancerous) or malignant (cancerous). Benign neoplasms are typically slow growing and do not spread to other parts of the body, while malignant neoplasms are aggressive, invasive, and can metastasize to distant sites.
Neoplasms occur when there is a dysregulation in the normal process of cell division and differentiation, leading to uncontrolled growth and accumulation of cells. This can result from genetic mutations or other factors such as viral infections, environmental exposures, or hormonal imbalances.
Neoplasms can develop in any organ or tissue of the body and can cause various symptoms depending on their size, location, and type. Treatment options for neoplasms include surgery, radiation therapy, chemotherapy, immunotherapy, and targeted therapy, among others.
Goiter is a medical term that refers to an enlarged thyroid gland. The thyroid gland is a small, butterfly-shaped gland located in the front of your neck below the larynx or voice box. It produces hormones that regulate your body's metabolism, growth, and development.
Goiter can vary in size and may be visible as a swelling at the base of the neck. It can be caused by several factors, including iodine deficiency, autoimmune disorders, thyroid cancer, pregnancy, or the use of certain medications. Depending on the underlying cause and the severity of the goiter, treatment options may include medication, surgery, or radioactive iodine therapy.
Hyperthyroidism is a medical condition characterized by an excessive production and release of thyroid hormones from the thyroid gland, leading to an increased metabolic rate in various body systems. The thyroid gland, located in the front of the neck, produces two main thyroid hormones: triiodothyronine (T3) and thyroxine (T4). These hormones play crucial roles in regulating many bodily functions, including heart rate, digestion, energy levels, and mood.
In hyperthyroidism, the elevated levels of T3 and T4 can cause a wide range of symptoms, such as rapid heartbeat, weight loss, heat intolerance, increased appetite, tremors, anxiety, and sleep disturbances. Some common causes of hyperthyroidism include Graves' disease, toxic adenoma, Plummer's disease (toxic multinodular goiter), and thyroiditis. Proper diagnosis and treatment are essential to manage the symptoms and prevent potential complications associated with this condition.
Iodine is an essential trace element that is necessary for the production of thyroid hormones in the body. These hormones play crucial roles in various bodily functions, including growth and development, metabolism, and brain development during pregnancy and infancy. Iodine can be found in various foods such as seaweed, dairy products, and iodized salt. In a medical context, iodine is also used as an antiseptic to disinfect surfaces, wounds, and skin infections due to its ability to kill bacteria, viruses, and fungi.
Neoplasms: Neoplasms refer to abnormal growths of tissue that can be benign (non-cancerous) or malignant (cancerous). They occur when the normal control mechanisms that regulate cell growth and division are disrupted, leading to uncontrolled cell proliferation.
Cystic Neoplasms: Cystic neoplasms are tumors that contain fluid-filled sacs or cysts. These tumors can be benign or malignant and can occur in various organs of the body, including the pancreas, ovary, and liver.
Mucinous Neoplasms: Mucinous neoplasms are a type of cystic neoplasm that is characterized by the production of mucin, a gel-like substance produced by certain types of cells. These tumors can occur in various organs, including the ovary, pancreas, and colon. Mucinous neoplasms can be benign or malignant, and malignant forms are often aggressive and have a poor prognosis.
Serous Neoplasms: Serous neoplasms are another type of cystic neoplasm that is characterized by the production of serous fluid, which is a thin, watery fluid. These tumors commonly occur in the ovary and can be benign or malignant. Malignant serous neoplasms are often aggressive and have a poor prognosis.
In summary, neoplasms refer to abnormal tissue growths that can be benign or malignant. Cystic neoplasms contain fluid-filled sacs and can occur in various organs of the body. Mucinous neoplasms produce a gel-like substance called mucin and can also occur in various organs, while serous neoplasms produce thin, watery fluid and commonly occur in the ovary. Both mucinous and serous neoplasms can be benign or malignant, with malignant forms often being aggressive and having a poor prognosis.
Autoimmune thyroiditis, also known as Hashimoto's disease, is a chronic inflammation of the thyroid gland caused by an autoimmune response. In this condition, the immune system produces antibodies that attack and damage the thyroid gland, leading to hypothyroidism (underactive thyroid). The thyroid gland may become enlarged (goiter), and symptoms can include fatigue, weight gain, cold intolerance, constipation, dry skin, and depression. Autoimmune thyroiditis is more common in women than men and tends to run in families. It is often associated with other autoimmune disorders such as rheumatoid arthritis, Addison's disease, and type 1 diabetes. The diagnosis is typically made through blood tests that measure levels of thyroid hormones and antibodies. Treatment usually involves thyroid hormone replacement therapy to manage the symptoms of hypothyroidism.
Thyroid hormone receptors (THRs) are nuclear receptor proteins that bind to thyroid hormones and mediate their effects in the body. There are two main types of THRs, referred to as THRα and THRβ.
THRα is a subtype of thyroid hormone receptor that is primarily expressed in tissues such as the heart, skeletal muscle, and brown adipose tissue. It plays an important role in regulating metabolism, growth, and development in these tissues. THRα has two subtypes, THRα1 and THRα2, which have different functions and are expressed in different tissues.
THRα1 is the predominant form of THRα and is found in many tissues, including the heart, skeletal muscle, and brown adipose tissue. It regulates genes involved in metabolism, growth, and development, and has been shown to play a role in regulating heart rate and contractility.
THRα2, on the other hand, is primarily expressed in the brain and pituitary gland, where it regulates the production of thyroid-stimulating hormone (TSH). THRα2 is unable to bind to thyroid hormones, but can form heterodimers with THRα1 or THRβ1, which allows it to modulate their activity.
Overall, THRα plays an important role in regulating various physiological processes in the body, and dysregulation of THRα function has been implicated in a number of diseases, including heart disease, muscle wasting, and neurological disorders.
Graves' disease is defined as an autoimmune disorder that leads to overactivity of the thyroid gland (hyperthyroidism). It results when the immune system produces antibodies that stimulate the thyroid gland, causing it to produce too much thyroid hormone. This can result in a variety of symptoms such as rapid heartbeat, weight loss, heat intolerance, and bulging eyes (Graves' ophthalmopathy). The exact cause of Graves' disease is unknown, but it is more common in women and people with a family history of the disorder. Treatment may include medications to control hyperthyroidism, radioactive iodine therapy to destroy thyroid tissue, or surgery to remove the thyroid gland.
Multiple primary neoplasms refer to the occurrence of more than one primary malignant tumor in an individual, where each tumor is unrelated to the other and originates from separate cells or organs. This differs from metastatic cancer, where a single malignancy spreads to multiple sites in the body. Multiple primary neoplasms can be synchronous (occurring at the same time) or metachronous (occurring at different times). The risk of developing multiple primary neoplasms increases with age and is associated with certain genetic predispositions, environmental factors, and lifestyle choices such as smoking and alcohol consumption.
Adenocarcinoma, papillary is a type of cancer that begins in the glandular cells and grows in a finger-like projection (called a papilla). This type of cancer can occur in various organs, including the lungs, pancreas, thyroid, and female reproductive system. The prognosis and treatment options for papillary adenocarcinoma depend on several factors, such as the location and stage of the tumor, as well as the patient's overall health. It is important to consult with a healthcare professional for an accurate diagnosis and personalized treatment plan.
Iodine radioisotopes are radioactive isotopes of the element iodine, which decays and emits radiation in the form of gamma rays. Some commonly used iodine radioisotopes include I-123, I-125, I-131. These radioisotopes have various medical applications such as in diagnostic imaging, therapy for thyroid disorders, and cancer treatment.
For example, I-131 is commonly used to treat hyperthyroidism and differentiated thyroid cancer due to its ability to destroy thyroid tissue. On the other hand, I-123 is often used in nuclear medicine scans of the thyroid gland because it emits gamma rays that can be detected by a gamma camera, allowing for detailed images of the gland's structure and function.
It is important to note that handling and administering radioisotopes require specialized training and safety precautions due to their radiation-emitting properties.
Papillary and follicular carcinomas are both types of differentiated thyroid cancer. They are called "differentiated" because the cells still have some features of normal thyroid cells. These cancers tend to grow slowly and usually have a good prognosis, especially if they are treated early.
Papillary carcinoma is the most common type of thyroid cancer, accounting for about 80% of all cases. It tends to grow in finger-like projections called papillae, which give the tumor its name. Papillary carcinoma often spreads to nearby lymph nodes, but it is usually still treatable and curable.
Follicular carcinoma is less common than papillary carcinoma, accounting for about 10-15% of all thyroid cancers. It tends to grow in round clusters called follicles, which give the tumor its name. Follicular carcinoma is more likely to spread to distant parts of the body, such as the lungs or bones, than papillary carcinoma. However, it is still usually treatable and curable if it is caught early.
It's important to note that while these cancers are called "papillary" and "follicular," they are not the same as benign (non-cancerous) tumors called papillomas or follicular adenomas, which do not have the potential to spread or become life-threatening.
A goiter is an abnormal enlargement of the thyroid gland, which is a butterfly-shaped endocrine gland located in the front of the neck. Goiters can be either diffuse (uniformly enlarged) or nodular (lumpy with distinct nodules). Nodular goiter refers to a thyroid gland that has developed one or more discrete lumps or nodules while the remaining tissue is normal or may also be diffusely enlarged.
Nodular goiters can be classified into two types: multinodular goiter and solitary thyroid nodule. Multinodular goiter consists of multiple nodules in the thyroid gland, while a solitary thyroid nodule is an isolated nodule within an otherwise normal or diffusely enlarged thyroid gland.
The majority of nodular goiters are benign and do not cause symptoms. However, some patients may experience signs and symptoms related to compression of nearby structures (such as difficulty swallowing or breathing), hyperthyroidism (overactive thyroid), or hypothyroidism (underactive thyroid). The evaluation of a nodular goiter typically includes a physical examination, imaging studies like ultrasound, and sometimes fine-needle aspiration biopsy to determine the nature of the nodules and assess the risk of malignancy. Treatment options depend on various factors, including the size and number of nodules, the presence of compressive symptoms, and the patient's thyroid function.
Skin neoplasms refer to abnormal growths or tumors in the skin that can be benign (non-cancerous) or malignant (cancerous). They result from uncontrolled multiplication of skin cells, which can form various types of lesions. These growths may appear as lumps, bumps, sores, patches, or discolored areas on the skin.
Benign skin neoplasms include conditions such as moles, warts, and seborrheic keratoses, while malignant skin neoplasms are primarily classified into melanoma, squamous cell carcinoma, and basal cell carcinoma. These three types of cancerous skin growths are collectively known as non-melanoma skin cancers (NMSCs). Melanoma is the most aggressive and dangerous form of skin cancer, while NMSCs tend to be less invasive but more common.
It's essential to monitor any changes in existing skin lesions or the appearance of new growths and consult a healthcare professional for proper evaluation and treatment if needed.
Medullary carcinoma is a type of cancer that develops in the neuroendocrine cells of the thyroid gland. These cells produce hormones that help regulate various bodily functions. Medullary carcinoma is a relatively rare form of thyroid cancer, accounting for about 5-10% of all cases.
Medullary carcinoma is characterized by the presence of certain genetic mutations that cause the overproduction of calcitonin, a hormone produced by the neuroendocrine cells. This overproduction can lead to the formation of tumors in the thyroid gland.
Medullary carcinoma can be hereditary or sporadic. Hereditary forms of the disease are caused by mutations in the RET gene and are often associated with multiple endocrine neoplasia type 2 (MEN 2), a genetic disorder that affects the thyroid gland, adrenal glands, and parathyroid glands. Sporadic forms of medullary carcinoma, on the other hand, are not inherited and occur randomly in people with no family history of the disease.
Medullary carcinoma is typically more aggressive than other types of thyroid cancer and tends to spread (metastasize) to other parts of the body, such as the lymph nodes, lungs, and liver. Symptoms may include a lump or nodule in the neck, difficulty swallowing, hoarseness, and coughing. Treatment options may include surgery, radiation therapy, and chemotherapy. Regular monitoring of calcitonin levels is also recommended to monitor the effectiveness of treatment and detect any recurrence of the disease.
A thyroid crisis, also known as thyrotoxic crisis or storm, is a rare but life-threatening condition characterized by an exaggerated response to the excess production of thyroid hormones (thyrotoxicosis). This condition can lead to severe hypermetabolic state, multi-organ dysfunction, and cardiovascular collapse if not promptly diagnosed and treated.
Thyroid crisis is often triggered by a stressful event, infection, or surgery in individuals with uncontrolled or poorly managed hyperthyroidism, particularly those with Graves' disease. The symptoms of thyroid crisis include high fever, tachycardia (rapid heart rate), hypertension (high blood pressure), agitation, confusion, delirium, vomiting, diarrhea, and sometimes coma.
The diagnosis of thyroid crisis is based on the clinical presentation, laboratory tests, and imaging studies. Treatment typically involves hospitalization in an intensive care unit, administration of medications to block the production and release of thyroid hormones, control heart rate and rhythm, correct electrolyte imbalances, and provide supportive care until the patient's condition stabilizes.