A rare malignant ovarian mixed germ cell tumor containing pancreatic tissue with islet cells

A rare ovarian mixed germ cell tumor containing pancreatic tissue with islet cells was reported. The tumor, weighing 4,500 g, arose in the left ovary of a 29-year-old nulliparous unmarried woman. On section, the tumor was largely solid, but with small- to medium-sized multiple cysts which contained mucinous fluid. Microscopically, the tumor was composed predominantly of immature pancreatic tissue with islet cells budding from the glandular structures, where a few aldehyde-fuchsin-positive cells and some argyrophil cells were seen. Also, insulin-, glucagon-, or somatostatin-reactive cells were localized in these structures by immunohistochemistry. Multiple cysts were covered by a monolayer of benign-looking mucinous epithelium. The tumor contained elements of dysgerminoma, endodermal sinus tumor, immature teratoma, and mucinous adenocarcinoma as minor components. Two years after the surgery followed by chemotherapy with vincristine, actinomycin D, and cyclophosphamide, the patient became pregnant and delivered a healthy female infant.