Primary yolk sac tumor of the endometrium: a case report and review of the literature.

A 49-year-old woman was admitted with abnormal vaginal bleeding of 5 months duration. Hysteroscopy showed polypoid formations in the uterine cavity. Biopsy of a polyp revealed an anaplastic malignant tumor. A total hysterectomy with bilateral salpingo-oophorectomy and iliac lymphadenectomy were performed. A polypoid soft white-yellowish tumor originated from the endometrium. The biopsies plus sections of the operative specimen were histologically similar and displayed typical features of yolk sac tumor (YST) with tubulo-papillary pattern. Schiller-Duval bodies and PAS-positive, diastase-resistant, hyaline droplets were present. There was no neoplastic involvement of the cervix, ovaries, and iliac lymph nodes. Tumor cells and hyaline globules were strongly immunoreactive with alpha-fetoprotein antibody. The patient refused chemotherapy and was subsequently treated by external radiotherapy. The patient remained free of disease 28 months after surgery. There are only four additional cases of primary YST of the endometrium reported in literature. On the basis of the small number of cases reported, such tumors appear to have clinical and pathological features similar to their ovarian counterparts.