Endocrine cell carcinoma of the uterine cervix.

We present an endocrine cell carcinoma of the uterine cervix in a 21-year-old woman which we studied by histochemical, immunocytochemical, and ultrastructural methods. The tumor had a histologic appearance similar to an oat cell carcinoma, and carcinoma in situ changes were found in the adjacent cervical surface epithelium. Histochemistry and electron microscopy revealed argyrophil cells containing small round secretory granules; more rarely argentaffin (enterochromaffin) cells were seen with dense, elongated and pleomorphic granules and numerous undifferentiated cells with few and small granules. Our findings indicate that the different types of endocrine tumor cells have the same stem cell origin and necessitate the revision of some of the concepts of the embryogenesis of the APUD cells and their tumors. We emphasize that all undifferentiated or poorly differentiated carcinomas of the uterine cervix should be examined histochemically and ultrastructurally, particularly since their correct classification has prognostic and therapeutic implications.