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 […]


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 […]

Cytologically benign follicular lesions

Cytologic diagnostic features low or moderate cellularity cohesive cells predominantly microfollicular pattern uniform, evenly spaced follicular cells round nucleus, finely granular chromatin scanty or moderate cytoplasm few macrophages bare nuclei Colloid is usually abundant, appearing as amorphous blobs or as a thin translucent film with bubbles and linear cracks. Some benign follicular lesions are hypercellular […]

Suspicious aspirate

Suspicious aspirate In some cases it may be difficult to differentiate between a benign and a malignant lesion, particularly as there may be overlapping cytological features. Follicular neoplasms are often reported in this category, it being difficult to differentiate between follicular/Hürthle cell carcinomas and adenomas cytologically. ‘Suspicious’ cases may be: suspicious for papillary carcinoma, suspicious […]

Cytologically suspicious follicular lesions

Cytologic diagnostic features: high cellularity predominantly microfollicular or trabecular pattern crowded, overlapping cells cellular alterations (mild atypia, an uniform enlargement) scanty or absent colloid Several of all of these features should be present to diagnose a follicular lesion as ‘cytologically suspicious’. Marked nuclear atypia is uncommon, and so are mitosis. Macrophages are absent. Bare nuclei […]

The Thy classification adopted by the Royal college of Physicians

Classification: Thy1: Non-diagnostic (inadequate or where technical artefact precludes interpretation; smears must contain 6 or more groups of at least 10 thyroid follicular cells to be considered adequate). Action: FNAC should be repeated with or without ultrasound guidance. Thy2: Non-neoplastic (features consistent with a nodular goitre or thyroiditis). Action: Two diagnostic benign results 3-6 months […]

Malignant tumours

Malignant tumours: Papillary carcinoma Poorly differentiated carcinomas (insular carcinoma) Anaplastic carcinoma Medullary carcinoma Lymphoma Metastatic carcinoma