Laparoscopic resection of a peritoneal inclusion cyst mimicking an ovarian borderline tumor

Abstract

A 70-year-old woman was referred with an adnexal mass present for several years that had enlarged from 3 to 5 cm during menopause and was suspected to be ovarian cancer. Magnetic resonance imaging showed a 5 cm pelvic mass with a 3 mm nodule in the tumor wall. The tumor had low-signal intensity on T1-weighted images and high-signal intensity on T2-weighted images, while the nodule showed low-signal intensity on T1- and T2-weighted images with contrast enhancement. Since an ovarian borderline tumor could not be ruled out, diagnostic laparoscopy was performed and confirmed the mass to be a peritoneal tumor, which was resected. Pathological examination revealed a benign peritoneal tumor, which was diagnosed as a peritoneal inclusion cyst. Peritoneal inclusion cysts are often confused with ovarian neoplasms because of their various appearances on imaging studies. In such cases, diagnostic laparoscopy is useful in ruling out malignancy.