Diagnosis & Discussion
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Microscopic description:
Cyto 1 and 2- follicular cells with moderate to abundant dense cytoplasm are present in a background of chronic inflammation; some of the follicular cells have pale nuclei with nuclear grooves.
Cyto 3,4,5- Images – Atypical follicular cells are present singly and in loosely cohesive groups. The cells have a moderate amount of cytoplasm, the nuclei have fine chromatin with irregular nuclear outlines, irregular grooves and inapparent to small nucleoli. Rare possible intranuclear inclusions are identified. Some cells have a plasmacytoid appearance. No colloid or inflammation is present in the background but a rare focus of dense extracellular material is identified.
FNA diagnosis:
Discussion:
Although the nuclear morphology of the tumor cells on cytology in this case have many features suggestive of papillary carcinoma, their frequent presence as single cells, an uncommon finding in papillary carcinoma, and their occasional plasmacytoid appearance, as well as the scattered fragments of extracellular material raised the possibility of medullary carcinoma. A cellblock was not available on which to perform immunohistochemical staining for thyroglobulin and calcitonin. However, medullary carcinomas are invariably associated with elevated serum calcitonin that can be easily measured.
Little evidence of hyperthyroidism was present other than the chronic inflammation since the patient had been under treatment for several months prior to sampling. Flame cells, cytoplasmic aggregates of mauve material, can be seen on Romanowsky stained smears in cases of Grave’s disease, but we only had Papanicolaou stained material. Lymphocytes are commonly found on aspirates of the thyroid in hyperthyroidism and suggest a relationship with Hashimoto’s thyroiditis.
The incidence of hyperthyroidism (Grave's disease) in papillary carcinoma is 4 percent. Papillary carcinoma arises more commonly in lymphocytic/Hashimoto's thyroiditis