Small cell carcinoma of the endometrium associated with adenosquamous carcinoma: a light and electron microscopic study.

This report describes a 64-year-old woman with a primary small cell carcinoma of the endometrium associated with adenosquamous carcinoma. The light microscopic features resembled those of small cell carcinoma of the lung and those of the uterine cervix, and foci of adenosquamous carcinoma lay scattered sparsely in the small cell carcinoma. Electron microscopy revealed cytoplasmic neurosecretory type granules. The neoplasm behaved in a very aggressive manner such that at 3 months after surgery a metastatic neoplasm appeared in the vagina. This case is a rare example of an endometrial carcinoma with differentiation toward endocrine as well as adeno and squamous cell carcinoma.