The significance of neuroendocrine expression in undifferentiated carcinoma of the endometrium.

Carcinomas with neuroendocrine (NE) differentiation have been associated with poor outcome in different organs. The purpose of this study was to evaluate the presence and significance of NE expression in a series of 46 undifferentiated endometrial carcinomas diagnosed between 1988 and 2005. NE expression was studied by immunohistochemistry including synaptophysin, chromogranin, and/or CD56. The patients' age ranged from 30 to 84 years (mean 55). Staging information was available for 45 cases and according to the International Federation of Gynecology and Obstetrics system they were distributed as follows: stage I (9 cases), stage II (2 cases), stage III (9 cases), and stage IV (25 cases). NE expression was present in 19/46 (41%) cases; however, it was diffuse in only 9% of the tumors. The median survival for patients without NE expression was 7 months (95% confidence interval 4-10 mo) and for patients with NE expression was 12 months (95% confidence interval 6-27 mo). The survival curves do not differ significantly (P=0.49). NE expression is common in undifferentiated carcinoma of the endometrium, as it was found in 41% of our cases. In most cases, NE expression is only focally present (< or =10% of the cells). There is no difference in overall survival in patients with or without NE expression.