Endometrial adenocarcinoma with a component of giant cell carcinoma.

We report six high-grade endometrial adenocarcinomas with a malignant giant cell component. The patients ranged in age from 43 to 85 years (mean 65); five were postmenopausal. All the patients presented with vaginal bleeding. The tumors all had a giant cell component that was composed of poorly cohesive sheets and nests of bizarre multinucleated giant cells admixed with an approximately equal number of mononucleate tumor cells. A sarcomatoid pattern and a marked inflammatory infiltrate were each present in three cases. All the tumors contained at least focal areas of endometrial adenocarcinoma of one of the usual types. Occasional malignant giant cells were positive for cytokeratins (AE1/AE3 or CAM 5.2) and epithelial membrane antigen in all three tumors tested. Three tumors were in stage I, one stage III and two stage IV. Two of the patients with stage I disease (each with superficial myometrial invasion) were alive and well 6 and 2 years later. Of the remaining four patients, three died of disease 2.5 years, 6 months, and 5 months after presentation, and one was alive with extensive abdominal disease after 1 year. Giant cell carcinoma of the endometrium is an aggressive tumor that should be distinguished from other endometrial tumors with a prominent giant cell component, including trophoblastic tumors, certain primary sarcomas, and malignant mixed müllerian tumors. It is imperative that malignant giant cells and non-neoplastic giant cells not be confused, as is possible in a curettage or biopsy specimen.