Thyroid adenoma

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Thyroid adenoma
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Thyroid adenoma
Specialty Oncology, endocrinology

A thyroid adenoma is a benign tumor of the thyroid gland, that may be inactive or active (functioning autonomously) as a toxic adenoma.

Contents

Signs and symptoms

A thyroid adenoma may be clinically silent ("cold" adenoma), or it may be a functional tumor, producing excessive thyroid hormone ("warm" or "hot" adenoma). In this case, it may result in symptomatic hyperthyroidism, and may be referred to as a toxic thyroid adenoma.

Diagnosis

Morphology

Thyroid follicular adenoma ranges in diameter from 3 cm on an average, but sometimes is larger (up to 10 cm) or smaller. The typical thyroid adenoma is solitary, spherical and encapsulated lesion that is well demarcated from the surrounding parenchyma. The color ranges from gray-white to red-brown, depending upon

  1. the cellularity of the adenoma
  2. the colloid content.

Areas of hemorrhage, fibrosis, calcification, and cystic change, similar to what is found in multinodular goiters, are common in thyroid (follicular) adenoma, particularly in larger lesions.

Types

Almost all thyroid adenomata are follicular adenomata. [1] Follicular adenomata can be described as "cold", "warm" or "hot" depending on their level of function. [2] Histopathologically, follicular adenomata can be classified according to their cellular architecture and relative amounts of cellularity and colloid into the following types:

Papillary adenomata are very rare. [3]

Differential diagnosis

Most common causes of hyperthyroidism by age. Causes of hyperthyroidism.png
Most common causes of hyperthyroidism by age.

A thyroid adenoma is distinguished from a multinodular goiter of the thyroid in that an adenoma is typically solitary, and is a neoplasm resulting from a genetic mutation (or other genetic abnormality) in a single precursor cell. [7] In contrast, a multinodular goiter is usually thought to result from a hyperplastic response of the entire thyroid gland to a stimulus, such as iodine deficiency.

Careful pathological examination may be necessary to distinguish a thyroid adenoma from a minimally invasive follicular thyroid carcinoma. [7]

Management

Most patients with thyroid adenoma can be managed by watchful waiting (without surgical excision) with regular monitoring. [8] However, some patients still choose surgery after being fully informed of the risks. [8] Regular monitoring mainly consists of watching for changes in nodule size and symptoms, and repeat ultrasonography or needle aspiration biopsy if the nodule grows. [8] For patients with benign thyroid adenomata, thyroid lobectomy and isthmusectomy is a sufficient surgical treatment. This procedure is also adequate for patients with minimally invasive thyroid cancer. When histological examination shows no signs of malignancy, then no further intervention is required. These patients should continue to have their thyroid hormone status regularly checked. [9]

Related Research Articles

Goitre

A goitre, or goiter, is a swelling in the neck resulting from an enlarged thyroid gland. A goitre can be associated with a thyroid that is not functioning properly.

Thyroid neoplasm

Thyroid neoplasm is a neoplasm or tumor of the thyroid. It can be a benign tumor such as thyroid adenoma, or it can be a malignant neoplasm, such as papillary, follicular, medullary or anaplastic thyroid cancer. Most patients are 25 to 65 years of age when first diagnosed; women are more affected than men. The estimated number of new cases of thyroid cancer in the United States in 2010 is 44,670 compared to only 1,690 deaths. Of all thyroid nodules discovered, only about 5 percent are cancerous, and under 3 percent of those result in fatalities.

Thyroidectomy

A thyroidectomy is an operation that involves the surgical removal of all or part of the thyroid gland. In general surgery, endocrine or head and neck surgeons often perform a thyroidectomy when a patient has thyroid cancer or some other condition of the thyroid gland or goiter. Other indications for surgery include cosmetic, or symptomatic obstruction. Thyroidectomy is a common surgical procedure that has several potential complications or sequelae including: temporary or permanent change in voice, temporary or permanently low calcium, need for lifelong thyroid hormone replacement, bleeding, infection, and the remote possibility of airway obstruction due to bilateral vocal cord paralysis. Complications are uncommon when the procedure is performed by an experienced surgeon.

Adenoma Type of benign tumor

An adenoma is a benign tumor of epithelial tissue with glandular origin, glandular characteristics, or both. Adenomas can grow from many glandular organs, including the adrenal glands, pituitary gland, thyroid, prostate, and others. Some adenomas grow from epithelial tissue in nonglandular areas but express glandular tissue structure. Although adenomas are benign, they should be treated as pre-cancerous. Over time adenomas may transform to become malignant, at which point they are called adenocarcinomas. Most adenomas do not transform. However, even though benign, they have the potential to cause serious health complications by compressing other structures and by producing large amounts of hormones in an unregulated, non-feedback-dependent manner. Some adenomas are too small to be seen macroscopically but can still cause clinical symptoms.

Lisch nodule

Lisch nodule, also known as iris hamartoma, is a pigmented hamartomatous nodular aggregate of dendritic melanocytes affecting the iris, named after Austrian ophthalmologist Karl Lisch (1907–1999), who first recognized them in 1937.

Benign tumor Disease of cellular proliferation that results in abnormal growths in the body which lack the ability to metastasize

A benign tumor is a mass of cells (tumor) that lacks the ability to either invade neighboring tissue or metastasize. When removed, benign tumors usually do not grow back, whereas malignant tumors sometimes do. Unlike most benign tumors elsewhere in the body, benign brain tumors can be life-threatening. Benign tumors generally have a slower growth rate than malignant tumors and the tumor cells are usually more differentiated. They are typically surrounded by an outer surface or stay contained within the epithelium. Common examples of benign tumors include moles and uterine fibroids.

Erythema induratum

Erythema induratum is a panniculitis on the calves. It occurs mainly in women, but it is very rare now. Historically, when it has occurred, it has often been concomitant with cutaneous tuberculosis, and it was formerly thought to be always a reaction to the TB bacteria. It is now considered a panniculitis that is not associated with just a single defined pathogen. The medical eponym Bazin disease was historically synonymous, but it applies only to the tuberculous form and is dated.

Cowden syndrome

Cowden syndrome is an autosomal dominant inherited condition characterized by benign overgrowths called hamartomas as well as an increased lifetime risk of breast, thyroid, uterine, and other cancers. It is often underdiagnosed due to variability in disease presentation, but 99% of patients report mucocutaneous symptoms by age 20-29. Despite some considering it a primarily dermatologic condition, Cowden's syndrome is a multi-system disorder that also includes neurodevelopmental disorders such as macrocephaly.

Thyroid disease

Thyroid disease is a medical condition that affects the function of the thyroid gland. The thyroid gland is located at the front of the neck and produces thyroid hormones that travel through the blood to help regulate many other organs, meaning that it is an endocrine organ. These hormones normally act in the body to regulate energy use, infant development, and childhood development.

Hürthle cell

A Hürthle cell is a cell in the thyroid that is often associated with Hashimoto's thyroiditis as well as benign and malignant tumors. This version is a relatively rare form of differentiated thyroid cancer, accounting for only 3-10% of all differentiated thyroid cancers. Oncocytes in the thyroid are often called Hürthle cells. Although the terms oncocyte, oxyphilic cell, and Hürthle cell are used interchangeably, Hürthle cell is used only to indicate cells of thyroid follicular origin.

Warthins tumor

Warthin's tumor, also known as papillary cystadenoma lymphomatosum, is a benign cystic tumor of the salivary glands containing abundant lymphocytes and germinal centers. It is named for pathologist Aldred Scott Warthin, who described two cases in 1929.

Toxic multinodular goitre

Toxic multinodular goiter (TMNG), also known as multinodular toxic goiter (MNTG), is an active multinodular goiter associated with hyperthyroidism.

Papillary thyroid cancer

Papillary thyroid cancer or papillary thyroid carcinoma is the most common type of thyroid cancer, representing 75 percent to 85 percent of all thyroid cancer cases. It occurs more frequently in women and presents in the 20–55 year age group. It is also the predominant cancer type in children with thyroid cancer, and in patients with thyroid cancer who have had previous radiation to the head and neck. It is often well-differentiated, slow-growing, and localized, although it can metastasize.

Endocrine disease

Endocrine diseases are disorders of the endocrine system. The branch of medicine associated with endocrine disorders is known as endocrinology.

Adrenal tumor

An adrenal tumor or adrenal mass is any benign or malignant neoplasms of the adrenal gland, several of which are notable for their tendency to overproduce endocrine hormones. Adrenal cancer is the presence of malignant adrenal tumors, and includes neuroblastoma, adrenocortical carcinoma and some adrenal pheochromocytomas. Most adrenal pheochromocytomas and all adrenocortical adenomas are benign tumors, which do not metastasize or invade nearby tissues, but may cause significant health problems by unbalancing hormones.

Thyroid nodule

Thyroid nodules are nodules which commonly arise within an otherwise normal thyroid gland. They may be hyperplastic or tumorous, but only a small percentage of thyroid tumors are malignant. Small, asymptomatic nodules are common, and often go unnoticed. Nodules that grow larger or produce symptoms may eventually need medical care. A goitre may have one nodule – uninodular, multiple nodules – multinodular, or be diffuse.

Follicular thyroid cancer

Follicular thyroid cancer accounts for 15% of thyroid cancer and occurs more commonly in women over 50 years of age. Thyroglobulin (Tg) can be used as a tumor marker for well-differentiated follicular thyroid cancer. Thyroid follicular cells are the thyroid cells responsible for the production and secretion of thyroid hormones.

Large-cell carcinoma is a heterogeneous group of undifferentiated malignant neoplasms that lack the cytologic and architectural features of small cell carcinoma and glandular or squamous differentiation. LCC is categorized as a type of NSCLC which originates from epithelial cells of the lung.

Respiratory bronchiolitis interstitial lung disease refers to a form of idiopathic interstitial pneumonia associated with smoking.

Noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) is an indolent thyroid tumor that was previously classified as an encapsulated follicular variant of papillary thyroid carcinoma, necessitating a new classification as it was recognized that encapsulated tumors without invasion have an indolent behavior, and may be over-treated if classified as a type of cancer.

References

  1. Cotran, Ramzi S.; Kumar, Vinay; Fausto, Nelson; Nelso Fausto; Robbins, Stanley L.; Abbas, Abulr9 K. (2005). Robbins and Cotran pathologic basis of disease. St. Louis, Mo: Elsevier Saunders. p. 1117. ISBN   978-0-7216-0187-8.
  2. "Endocrine Pathology" . Retrieved 2009-05-08.
  3. 1 2 3 4 5 emedicine > Thyroid, Evaluation of Solitary Thyroid Nodule > Benign Thyroid Nodules By Daniel J Kelley and Arlen D Meyers. Updated: Oct 17, 2008
  4. TheFreeDictionary > microfollicular adenoma Citing: Dorland's Medical Dictionary for Health Consumers. Copyright 2007
  5. Ünlütürk, U; Karaveli, G; Sak, S. D.; Erdoğan, M. F. (2011). "Hyalinizing trabecular tumor in a background of lymphocytic thyroiditis: A challenging neoplasm of the thyroid". Endocrine Practice. 17 (6): e140–3. doi:10.4158/EP11138.CR. PMID   21940281.
  6. Carlé, Allan; Pedersen, Inge Bülow; Knudsen, Nils; Perrild, Hans; Ovesen, Lars; Rasmussen, Lone Banke; Laurberg, Peter (2011). "Epidemiology of subtypes of hyperthyroidism in Denmark: a population-based study". European Journal of Endocrinology. 164 (5): 801–809. doi: 10.1530/EJE-10-1155 . ISSN   0804-4643.
  7. 1 2 Ramzi Cotran; Vinay Kumar; Tucker Collins (1999). Robbins Pathologic Basis of Disease, 6th Edition. W.B. Saunders. ISBN   978-0-7216-7335-6.
  8. 1 2 3 Treatment section in: Welker, M.; Orlov, D. (2003). "Thyroid nodules". American Family Physician. 67 (3): 559–566. PMID   12588078.
  9. Mulita, Francesk; Anjum, Fatima (2020), "Thyroid Adenoma", StatPearls, Treasure Island (FL): StatPearls Publishing, PMID   32965923 , retrieved 2020-11-07
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