Medullary thyroid carcinoma : Rare cytologic findings

OBJECTIVE: To describe some rare cytologic findings in medullary thyroid carcinoma. STUDY DESIGN: Review of the fine needle aspiration smears from 15 cases of medullary thyroid carcinoma that were confirmed on histologic sections. The ages ranged between 31 and 67 years; 10 were female and 5 male. Thirteen were sporadic forms, and two were familial forms. RESULTS: Eight cases were classified as pleomorphic cell type and seven as monomorphic cell type. The smears revealed round, oval, triangular, polygonal and spindle-shaped cells, intracytoplasmic red granules, occasional intranuclear inclusions, amyloid, binucleated and multinucleated cells, and thick, granular chromatin. CONCLUSION: The rare cytologic findings in this study were grape cells, cytoplasmic nippling, elongated cytoplasmic processes, carrot-shaped nuclei, nuclear buddings, mast cell-like cells and a Burkitt's lymphoma-like appearance. These findings were rarely reported before.