Hepatoid carcinoma of the uterus that collided with carcinosarcoma

The case of a 68-year-old woman who was seen at Tokyo Kousei Nenkin Hospital because of abnormal genital bleeding is described. A malignant uterine tumor was suspected based on biopsy results. Hysterectomy and bilateral salpingo-oophorectomy were performed. Grossly, a solid whitish tumor occupied the area from the endocervix to the uterine body. On the consecutive fundal side, a whitish tumor protruded into the uterine cavity. Histologically, the tumor occupying the endocervical side showed a trabecular growth pattern. Many periodic acid-Schiff (PAS)-positive hyaline globules were observed. The cytoplasm of the tumor cells and the hyaline globules were immunohistochemically positive for alpha-fetoprotein (AFP). The tumor occupying the fundal side was identified as having endometrioid adenocarcinoma and spindle cell sarcoma components. The two tumors collided at a clear boundary. The present case was pathologically diagnosed as a collision cancer involving a hepatoid carcinoma and a carcinosarcoma. To our knowledge, this is the fourth reported case of a hepatoid carcinoma of the uterus. When no lesion is detected in the liver and stomach of a patient whose serum AFP level is abnormally high, the female reproductive system, such as the ovaries and uterus, should be examined as a possible site of AFP-producing cancer.