Early form of ovarian cancer originating in inclusion cysts - A case report

BACKGROUND: Most surface epithelial-stromal tumors of the ovary are thought to arise from epithelial inclusion cysts; thus, those cysts and the origin al surface epithelium are precursor lesions of ovarian carcinoma. CASE: A 46-year-old woman underwent a hysterectomy, right salpingo-oophorec tomy and wedge biopsy of the left ovary because of a uterine myoma and righ t dermoid cyst. Histologic examination incidentally showed a tiny focus of well-differentiated serous carcinoma originating in inclusion cysts in the biopsied left ovary. Relaparotomy was performed, and only metaplastic epith elium in the inclusion cysts was found in the remnant of the left ovary. Th is finding was thought to be the origin of an ovarian cancer. CONCLUSION: Carcinoma precursors should occur in epithelial inclusion cysts of the ovary, as in the cervix and endometrium, but have been reported onl y rarely. Their incidental finding may help identify patients at risk of de veloping ovarian carcinoma.