Undifferentiated carcinoma of the endometrium. A histopathologic and clinical study of 31 cases.

A histopathologic review of 1985 cases of endometrial carcinoma yielded 31 undifferentiated carcinomas (1.6%). Forty-eight percent were large cell type and 52%, intermediate/small cell type. Twenty-one tumors were examined immunohistochemically. All stained for keratin. Eleven tumors reacted with vimentin antibodies, two with carcinoembryonic antigen antibodies, and ten with neuron-specific enolase (NSE) antibodies (four of which stained for bombesin, two for beta-endorphin, one for prealbumin, five for Leu7, and four for synaptophysin). The mean age at diagnosis was 63.9 years (range, 45 to 86). The crude 5-year and 10-year survival was 58% and 48%, respectively. Seventy-nine percent of the patients in surgicopathologic Stage I and 33% in Stage II survived 5 years. The intermediate/small cell types had a somewhat better prognosis than the large cell type, but the difference was not statistically significant. The presence or absence of NSE and vimentin immunoreactivity had no influence on survival. All patients with tumors infiltrating less than one half of the myometrium survived 5 years in contrast with 46% of the patients with deep infiltrating tumors. Fifty-four percent of the patients with demonstrable vessel invasion survived 5 years in contrast with 89% not so affected.