Localized malignant pleural mesothelioma (LMPM) is a rare tumor with good prognosis by surgical resection. We report an atypical case of malignant pleural sarcomatoid mesothelioma (SM) in an asymptomatic 65-year-old woman, who had no history of exposure to asbestos. She presented with a small pleural mass without pleural effusion and was misdiagnosed as a benign localized fibrous tumor (BLFT) on pathologic examination through a surgical tumor specimen. However, seven months later, the patient returned with serious cancerous symptoms. A large recurrent tumor mass was found within the chest wall invading at the old surgical resection site. SM, a subtype of LMPM, was confirmed with histopathogy and immunohistochemisty. In conclusion, malignant pleural mesothelioma (MPM) can present with typical radiologic finding similar to a BLFT, and has a wide histopathologic presentation in biopsy specimen. A thorough pathologic investigation should be attempted even when a pleural mass resembles benign, localized, and small on radiologic studies.
Spontaneous pneumothorax (SP), as the first manifestation of lung cancer, is relatively rare, with reported occurrence rate of between 0.03% and 0.05%. The mechanism of concurrent pneumothorax with lung cancer is not clear, however several theories were proposed, including tumor necrosis mechanism and rupture of the bulla which contains tumor. We herein report two cases of lung cancer, in which the initial manifestations was only limited to SP. Without any radiologic abnormalities preoperatively, wedge resection of bullatous lung and subsequent histologic study followed. Pathologic study revealed the presence of bullatous change of the lung and combined lung cancer.