Medullary carcinoma

Medullary thyroid carcinoma (MTC) accounts for about 5% of thyroid cancers. Differently from the other carcinomas, which arise from the follicular cells, medullary carcinoma arises from parafollicular cells (C cells) of the thyroid, which synthetize calcitonin. About 80-90% are sporadic and occur in adults, the rest occur in children in genetic syndromes called multiple endocrine […]

Insular carcinoma

Poorly differentiated carcinomas (insular carcinoma) Some thyroid carcinomas have an intermediate grade of atypia between well-differentiated carcinomas and anaplastic carcinoma. These poorly differentiated carcinomas account for <5% of thyroid carcinomas. One distinctive form is insular carcinoma.  Cytologic diagnostic features high cellularity mostly single cells clusters, microfollicles monomorphous round nuclei  On hystologic preparations, malignant cells of […]

Anaplastic carcinoma

It accounts for less than 5% of thyroid cancers and it is associated with a very poor prognosis. It presents clinically as a rapidly growing neck mass which usually has already infiltrated adjacent structures at the time of diagnosis. In about one-third of cases, anaplastic carcinoma is associated to a well-differentiated thyroid carcinoma (such as […]

Lymphoma

Primary thyroid non-Hodgkin lymphoma (PTNHL) is a rare neoplasm, which typically occurs in older-aged women in the setting of Hashimoto`s thyroiditis. The risk for a patient with thyroditis is much greater than in the general population, but occurrence of a lymphoma is very rare. Most patients present with an enlarging neck mass and cervical lymph […]

Metastatic carcinoma

The breast, the kidney and the lungs are the most common primary sites of metastatic tumors to the thyroid. This possibility should be considered if the cytologic pattern does not conform with common neoplasms or the patient has a history of cancer elsewhere. In many cases, however, there is no clinical history of malignancy. Metastatic […]

Evaluation of the specimen

Several features will be considered in the evaluation of the specimen: the type of cells (such as thyrocytes, macrophages, lymphocytes) Thyrocytes and macrophages. Fluid colloid in the background, bland thyrocytes and pigmented macrophages. Lymphocytes and thyrocytes. A group of bland thyroid cells showing a follicular arrangement, surrounded by smaller lymphoid cells with little amount of identifiable cytoplasm. […]

Multinodular goitre

It is a nodular enlargement of the gland, due to derangements in hormone production, which is often asymmetric and sometimes extreme. Follicular cells undergo hyperplasia, leading to the formation of several nodules. The nodules, which are usually not encapsulated, may considerably vary in their microscopic appearance: some of them are composed of very large macrofollicles […]

Papillary carcinoma

Papillary thyroid carcinoma (PTC) is the most common malignancy of the thyroid (>80% of thyroid cancers). It may occur at any age, but most patients are between 30 and 50 years old; most of them are female (F:M 3:1). It usually presents as a solitary, non-functioning (‘cold’) nodule, sometimes with cervical lymphadenopathy due to metastatization. […]

Terminology for reporting results

Terminology for reporting results It is advisable to use diagnostic categories such as “negative” (benign), “suspicious”, “positive” (malignant) and “non-diagnostic” (unsatisfactory), followed by a description. Negative (benign) aspirate Positive (malignant) aspirate Suspicious aspirate An increasingly used classification identifies five categories basically splitting the suspicious category into probably reactive (T3 – low risk of malignancy) and […]

Radiation changes

Long-term morphologic changes may occur in the thyroid of patients who undergo external irradiation of the neck (usually as a therapy of malignancies) or administration of radioactive iodine (which is used to treat hyperthyroidism). Cytologic diagnostic features sheets (macrofollicles) enlarged cells normal N/C ratio Hürthle cell change cytoplasmic vacuolization marked nuclear atypia: marked size variation […]