ENCAPSULATED FOLLICULAR THYROID-CARCINOMA EXHIBITING GLANDULAR AND SPINDLE-CELL COMPONENTS - A CASE-REPORT

We describe art unusual case of a thyroid carcinoma exhibiting glandul ar and sarcomatous features. The tumor occurred in a 16-year-old girl. Histologic study of the resected thyroid gland revealed an encapsulat ed tumor composed predominantly of glandular structures and some solid areas. In the glandular areas, the tumor cells showed a cribriform gr owth pattern, and neither colloid secretion into the lumen nor clear-c ut cytologic features suggestive of papillary or follicular thyroid ca rcinoma were observed. lit the solid areas, tumor cells became spindle d and showed a sarcomatous arrangement with occasional whorl formation . A transition from the glandular areas to the solid ones was observed . Immunohistochemical study revealed that tumor cells were positive fo cally for epithelial membrane antigen, cytokeratin and secretory compo nent. Thyroglobulin was positive only in a few and limited areas of th e glandular component. Calcitonin was negative throughout the tumor. T he histologic and immunohistochemical evidence indicates that this tum or is of thyroid origin and is probably derived from thyroid follicula r cells. The histology of this tumor is unique, so we report this case briefly.