Abstract
A 53-year-old woman presented with a right inguinal mass was diagnosed as having a right inguinal cystic tumor and external inguinal hernia on a CT scan, and was operated on in our hospital. After high ligation of the hernia sac, the tumor was resected and a hernia repair was performed. The lesion was clarified to be multicystic solid tumor. Histopathology revealed the cells covering the intracystic wall to be mesothelial cells. On immunohistochemical staining, the cells were positive for calretinin and cytokeratin and negative for EMA, leading to the diagnosis of benign multicystic peritoneal methothelioma. She has been free from recurrence, as of 2 years after the operation. Although benign multicystic peritoneal mesothelioma is a rare entity, it often recurs after the surgery and hence demands radical operation. Benign multicystic peritoneal mesothelioma of the inguinal region is often associated with inguinal hernia where a possible contribution of chronic inflammation of the hernia is suggested. Out of five cases of inguinal benign multicystic peritoneal mesothelioma including our case, no postoperative recurrence has occurred in four cases. The tumors arisen in the inguinal region exist close to the body surface and grow in a localized area, so that it can be detected in an early stage, together with the presence of inguinal hernia, and can be resected radically.
