Adenoid cystic ovarian carcinoma compared with other adenoid cystic carcinomas of the female genital tract.

Adenoid cystic carcinoma (ACC) of the ovary is an extremely rare neoplasm referred to infrequently in the literature. A new case of a pure, primary, ovarian ACC is reported. The patient was a 45-year-old white woman who had a stage IA, well-circumscribed, unilateral, ovarian mass. Histologically, the tumor was composed of small, uniform, and basaloid cells exhibiting predominantly a tubular pattern, as well as demonstrating cribriform and focal solid areas. There was no necrosis and minimal nuclear pleomorphism; the mitotic rate was fewer than three cells per 10 high-power fields. Immunohistochemical examination showed that the tumor cells were strongly positive for cytokeratins CAM 5.2 and AE1/3 and carcinoembryonic antigen. The cells at the periphery of the epithelial aggregates in the cribriform and tubular areas were positive for muscle-specific actin and, occasionally, for S100 protein. Electron microscopic examination revealed that these cells had convoluted nuclei and filamentous structures associated with dense bodies. These findings support a myoepithelial component. A characteristic feature was the production of periodic acid-Schiff stain-positive basement membrane material, which appeared as reduplicated basal lamina by electron microscopic examination. The patient is currently alive, without evidence of recurrence or persistent tumor 7 years after surgical excision. The tumor demonstrated immunohistochemical and ultrastructural findings similar to those of ACCs of salivary gland origin and to other ACCs of the female genital tract. The histogenesis of most ovarian ACCs is through metaplasia of the celomic epithelium, but pure cases might also be of teratomatous origin.