Cytologic diagnosis of medullary carcinoma of the thyroid gland

Abstract

Fine needle aspiration cytology (FNAC) has been evaluated as a diagnostic method for medullary carcinoma of the thyroid gland (MCT) in 22 patients with verified hereditary or sporadic MCT. Out of all cases, there was one case of multiple endocrine adenomatosis type II with MCT and pheochromocytoma. An adequate bioptic yield was obtained in 18 patients. In eight cases, immunocytochemical techniques for calcitonin, thyroglobulin and carcinoembryonic antigen were used. The typical MCT cell was asymmetrical, sometimes triangular and often with a characteristic red granulation in May-Grünwald-Giemsa staining. The presence of spindle cells in addition to these polygonal cells Is a common feature and significant clue to the diagnosis. Eccentrically positioned, bi/multiple nuclei were common. Amyloid, when present, can be seen both intra- and extracellularly.