Amphicrine--composite calcitonin and mucin-producing--carcinoma of the thyroid.

A case of thyroid carcinoma in a 38-year-old male with a high serum level of calcitonin is reported. The tumor was composed of polygonal argyrophilic cells, signet ring Alcian blue-positive cells, and a minority of amphicrine elements. The same polymorphic cellular component was seen at the ultrastructural level. Anticalcitonin immunoperoxidase revealed that the majority of cells were positive, including the amphicrine cells. In spite of calcitonin production it is felt that cases similar to the present one should be distinguished from "ordinary medullary" carcinoma and the terms "amphicrine" or "composite calcitonin and mucin-producing carcinoma" are proposed.