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 original surface epithelium are precursor lesions of ovarian carcinoma.

CASE

A 46-year-old woman underwent a hysterectomy, right salpingo-oophorectomy and wedge biopsy of the left ovary because of a uterine myoma and right 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 epithelium in the inclusion cysts was found in the remnant of the left ovary. This 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 only rarely. Their incidental finding may help identify patients at risk of developing ovarian carcinoma.