[Pseudomesotheliomatous carcinoma of the lung].

Pseudomesotheliomatous carcinoma is the lung cancer with marked pleural extension resembling malignant pleural mesothelioma on diagnostic imaging. We report a rare case of pseudomesotheliomatous carcinoma of the lung in a 72-year-old man. The patient had complained of dyspnea and a chest roentgenogram showed right pleural effusion. Computed tomography (CT) of the chest revealed diffuse irregular pleural thickening, which mimicked pleural malignant mesothelioma. Pleural tissue sampling was performed to obtain definitive diagnosis by video-assisted thoracoscopic surgery. At the operation. the tumor was found to have a spread along the pleural surface and primary lesion was not detected in the right lung parenchyma. Immunohistochemically, the tumor was positive for carcinoembryonic antigen (CEA), but negative for calretinin, thrombomodulin, and pulmonary surfactant apoprotein. Final diagnosis was adenocarcinoma of the lung.