Ovarian endometrioid carcinoma with diffuse pigmented peritoneal keratin granulomas: a case report and review of the literature.

The presence of keratin granulomas in peritoneal cavity associated with ovarian endometrioid carcinoma, which might be related to leakage from the ovarian tumor, is rarely reported. Its clinical significance has not yet been well investigated. We report a case presenting with intermittent abdominal pain after an acute episode 1 month before a complex adnexal tumor was noted. Comprehensive cytoreductive surgery was performed. The ovarian tumor was an endometrioid adenocarcinoma with squamous differentiation. There were diffuse brownish flecks over the omental surface and pelvic peritoneum, which contained fragments of degenerated squamous cells, keratin, and numerous foreign body giant cells. Extensive multiple sections were examined for these implants. DNA flow cytometry and various immunostaining studies (HER-2/neu, p53, CK-7, and cytokeratin [AE1/AE3]) were performed. Since viable epithelial cells in the implants could be differentially identified against mesothelial or granulomatous components by CK-7 staining and DNA aneuploidy was demonstrated on primary ovarian tumor, four courses of chemotherapy were administered. The patient has been free of disease for 18 months since diagnosis.