A Case of Malignant Peritoneal Mesothelioma with Multiple Early Gastric Cancers

Abstract

We report a case of malignant peritoneal mesothelioma with multiple early gastric cancers. A 70-year-old man admitted for a bleeding gastric ulcer had the gastric ulcer cured by suitable medication, but gastrointestinal fiber showed 3 early gastric cancers, necessitating distal gastrectomy with lymph node dissection. Intraoperative findings included thickened, hard, whitish, granulated lesions under the bilateral diaphragm, greater and lesser omentum, surface of the transverse colon, and mesenterium transversum. We suspected that lesions were dissemination of gastric cancer, although the cancer was thought to be in the early stage. We conducted peritoneal biopsy. Histopathologically, all 3 gastric lesions were early gastric cancer, but the peritoneal lesion suspected of dissemination was malignant peritoneal mesothelioma. Differential diagnosis between dissemination of gastrointestinal cancer with malignant peritoneal mesothelioma is very difficult. It is thus important to conduct peritoneal biopsy, even for lesions due to suspected to dissemination.