A case of diffused malignant pleural mesothelioma forming small multiple disseminations with intraoperatively suspicious carcinoid tumors.

A 65-year-old male, having symptoms suggestive of pulmonary malignant tumor, underwent video-assisted thoracic surgery (VATS). Surgery revealed a solid tumor originating from the thoracic wall, with many small solid tumors in the thoracic wall and diaphragm near the tumor. The intraoperative observation of a frozen section typed the tumor as carcinoid; however, hematoxylin-eosin staining and immunohistological findings provided the definitive diagnosis of diffused, malignant pleural mesothelioma (MPM).