Uterine papillary serous carcinoma: a highly malignant form of endometrial adenocarcinoma

A review of 256 cases of pathologic Stage I uterine adenocarcinoma treated at Stanford University Hospital revealed 26 cases of uterine papillary serous carcinoma (UPSC), a clinically aggressive and morphologically distinct variant of adenocarcinoma which closely resembles ovarian papillary serous carcinoma. These lesions are easily recognized by microscopic examination and typically feature a high degree of cytologic anaplasia and a papillary growth pattern. Invasion of the lymphatics has been a frequent finding. The relapse rate among patients with pathologic Stage I UPSC was 50% (13/26), five times the rate which would have been predicted by the incidence of UPSC. Patients with Stage I UPSC fared significantly worse than the group of nonpapillary grade II or grade III adenocarcinomas (p less than 0.0001). Forty percent of Stage I UPSC patients had deep myometrial invasion, as compared with 12% of those with all other histologic types of adenocarcinoma (p = 0.001). Women with UPSC deeply invading the myometrium tended to do worse than those with deeply invasive lesions of the more usual endometrioid type as reflected by relapse rates (after surgery alone) of 63% and 30%, respectively. Of seven Stage I corpus carcinoma patients whose initial site of failure was in the upper abdomen, six had UPSC. Thus, UPSC shares the tendency of its ovarian counterpart to spread over peritoneal surfaces. In addition to the original study group of 26 Stage I patients, 34 patients with more advanced stages of UPSC were also reviewed. Of these, 26 have been followed and four survive. Eleven of these women presented or relapsed with abdominal carcinomatosis. UPSC is a clinically aggressive neoplasm which should be distinguished from other types of primary endometrial adenocarcinoma. In cases of invasive UPSC the mode of spread, similar to that of ovarian surface epithelial carcinomas, suggests the need for adjuvant upper abdominal and pelvic irradiation or effective chemotherapy.