A Rare Cause of Massive Abdominal Distension: Giant Benign Cystic Mesothelioma of the Mesentery

Benign cystic mesothelioma (BCM) of the mesentery is an exceptionally rare intra- abdominal neoplasm of mesothelial origin. It commonly presents as a large cystic mass with nonspecific abdominal symptoms, making preoperative diagnosis challenging. We report a case of a 49-year-old female who presented with progressive abdominal distension and pain. Imaging revealed a giant multiloculated cystic mass. The patient underwent exploratory laparotomy with complete surgical excision. Histopathology and immunohistochemistry confirmed benign cystic mesothelioma. The postoperative course was uneventful with no recurrence on follow-up. Complete surgical excision remains the treatment of choice and offers excellent prognosis.