ABSTRACT
Strumal carcinoma of the ovary is rare tumor of germ cell origin characterized by intimate mixture of thyroid tissue and carcinoid. We report a strumal carcinoid tumor associated with ipsilateral follicular cyst and contralateral mature cystic teratoma of the ovary in a 47-year-old woman. Histologically it was composed largely of trabeculae partly of insular carcinoid and focally of individual thyroid follicles. Many cells in the carcinoid areas and even some follicular areas contained abundant argyrophile granules, and they also, in the corresponding areas, demonstrated thyroglobulin. Electron microscopic findings revealed abundant neurosecretory granules and colloid material in the same cell. We agree that this tumor is derived from hybrid showing thyroid and neuroendocrine differenciation.