Ovarian mucinous cystadenocarcinoma producing alpha-fetoprotein. A case report.

A 62-year-old woman with a complaint of abdominal distention 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.