Alpha-fetoprotein producing uterine corpus carcinoma: A hepatoid adenocarcinoma of the endometrium.

A case of alpha-fetoprotein (AFP) producing endometrial carcinoma in a 60-year-old Japanese woman is presented. The patient complained of abnormal vaginal bleeding of 10 days' duration. On admission a uterine corpus mass and high serum AFP concentration (31950 ng/mL) was noted. There was no tumorous lesion in any other organ radiographically and endoscopically. Histologically, the biopsy specimen taken from the uterine mass showed a poorly differentiated endometrial carcinoma and a radical hysterectomy was subsequently performed. The postoperative serum AFP value transiently decreased with chemotherapy, however, lung metastases were found and the patient died 12 months following surgery. The resected uterus had a necrotic tumor, 6 x 5 x 4 cm in size, filling the endometrial cavity, characterized by exophytic growth with infiltration in the myometrium. Histologically, the tumor was composed of the main medullary carcinoma area with microcysts and admixed small areas of well-differentiated endometrioid adenocarcinoma, accompanied by a smooth transition with one another. In both the areas, the tumor cells had immunoreactive AFP, alpha-1-antitripsin, albumin, transferrin, carcinoembryonic antigen, CA19-9, and epithelial membrane antigen. There was no histologic evidence for a germ cell tumor. Based on these findings, this uterine corpus tumor was regarded as hepatoid variant of endometrial carcinoma. Although the histogenesis remains controversial, we assume the hypothesis that the tumor may arise in the endometrium per se in association with abnormal differentiation of muellerian duct elements.