[Primary insular carcinoid tumor in a benign cystic teratoma of the ovary (author's transl)].

A case of primary, insular, argentaffin carcinoid tumor (argentaffinoma) of the left ovary, arising in a bening cystic teratoma in a 60-year-old woman is reported. The tumor was not accompanied by any signs of the carcinoid syndrome despite a large volume, prominent acinar differentiation, and strong argentaffinity. Considering the morphologic carcinoid classification by Soga and Tazawa, the case had a mixed A + C pattern. A few Paneth-like cells and a few small calcifications in the stroma were present. Microscopic, ultrastructural, and histochemical findings were identical with those of carcinoids arising in midgut derivatives. There were small mucinous areas about 1.5 cm in diameter. Microscopic examination revealed pools of mucin with more of less disintegrated acini. This morphologic feature was not as yet reported in the insular carcinoid tumor. The patient feels well one and half year after hysterectomy and bilateral salpingo-oophorectomy, without any signs of metastatic disease.