Small cell carcinoma of the endometrium: light microscopic and immunohistochemical study of a case.

Small cell carcinoma of the endometrium is extremely rare. The clinical behaviour of this tumour is usually very aggressive. The histopathological distinction of endometrial small cell neuroendocrine carcinoma from mesodermal mixed tumours has important prognostic and therapeutic implications. The case of a 62-year-old white female suffering from postmenopausal bleeding is presented. Macroscopic examination revealed a bulky intraluminal mass with infiltration of more than half of the myometrial wall. In H&E-stained sections atypical small tumour cells revealing neuroendocrine features were found. Immunohistochemical evidence of neuroendocrine differentiation was demonstrated using the markers neuron-specific enolase and synaptophysin. The patient died three months after diagnosis.