Columnar cell carcinoma of the thyroid

A case of columnar cell carcinoma of the thyroid occurring in a 50-yearoid female is described. Histologically, the 2 cm tumor showed a prominent papillary architecture with thin fibrous cores covered by columnar cells and marked nuclear stratiflcation. It also showed microfollicular, glandular, and solid pattems. The nuclear features were different to those of conventional papillary carcinomas and similar to those of follicular tumors. The tumor was principally encapsulated with vascular and minimal capsular invaslon. The tumor cells were positive for thymglobulin. The tumor was DNA diploid with a low S phase fraction as determined by flow cytometry. The patient had no lymph node or distant metastasis. The patient was well and without disease 9 months after surgery. The possibility that the neoplasm is one of poorly differentiated thyroid carcinomas rises.