Abstract
A 68-year-old man was admitted with a provisional diagnosis of left inguinal mass lesion. Abdominal computed tomography showed pleural hypertrophy with calcification and ascites. Gastrointestinal fiberscopic study and abdominal sonography showed no other abnormal findings. Physical examination revealed a tender left inguinal mass, which could not be reduced. We suspected left inguinal hernia with invagination of the greater omentum as diagnosis. The patient had worked with exposure to asbestos for 38 years, so we could not exclude carcinomatous peritonitis. However, preoperative examinations showed no evidence of a primary cancer of any organ and the gastroenterological tumor markers were negative. Thus, we performed a herniorrhaphy for the left inguinal hernia and investigated the nature of the ascites. There were many nodules on the hernia sac and in the peritoneum, and a good amount of serous ascites in the abdominal cavity. The cytology was Group V and the pathology was malignant peritoneal mesothelioma (biphasic form). The patient is currently receiving combination chemotherapy consisting of pemetrexed sodium hydrate and cis-diammine dichloro platinum. We experienced a case of malignant peritoneal mesothelioma diagnosed during herniorrhaphy for left external inguinal hernia.
