COLUMNAR CELL-CARCINOMA OF THE THYROID

A case of columnar cell carcinoma of the thyroid occurring in a 50-yea r-old female is described. Histologically, the 2 cm tumor showed a pro minent papillary architecture with thin fibrous cores covered by colum nar cells and marked nuclear stratification. It also showed microfolli cular, glandular, and solid patterns. The nuclear features were differ ent to those of conventional papillary carcinomas and similar to those of follicular tumors. The tumor was principally encapsulated with vas cular and minimal capsular invasion. The tumor cells were positive for thyroglobulin. The tumor was DNA diploid with a low S phase fraction as determined by flow cytometry. The patient had no lymph node or dist ant metastasis. The patient was well and without disease 9 months afte r surgery. The possibility that the neoplasm is one of poorly differen tiated thyroid carcinomas rises.