Ovarian Mucinous Cystadenocarcinoma Producing aIpha‐Fetoprotein:A Case Report

A 62- year- old woman with a complaint of abdominal dis-tention underwent surgery to remove a tumor in her left ovary. The serum alpha- fetoprotein (AFP) level was 4,130 ng/ml. Histologically, the tumor was diagnosed as a mucinous cystadenocarcinoma with a small area of solid proliferation of tumor cells. The cells of the latter part were shown immunohistochemically to possess AFP. We suppose that a part of the mucinous cystadenocarcinoma dedifferentiates and produces AFP. Acta Pathol Jpn 42: 372–375. 1992.