[A case of malignant lymphoma diagnosed by thoracoscopy with local anesthesia]

A 67-year-old woman was hospitalized with right pleural effusion on chest radiography. Chest CT showed a thickened parietal pleura and pleural effusion in the right thorax. Cytological examination of pleural effusion showed atypical plasma cells. We performed thoracoscopy with local anesthesia for diagnosis and observed an about 5 x 5 cm seized red soft tumor on the parietal pleura. Pathological and immunohistochemical examination of the pleural tumor revealed that it was marginal zone B-cell malignant lymphoma. In this case, we could not reach a diagnosis only by cytological examination of the pleural effusion. Thoracoscopy with local anesthesia was safe and useful for diagnosis of malignant lymphoma with pleural effusion. Most cases of primary pleural malignant lymphoma have a history of chronic pyothorax. This case is thought to be a very rare case of primary pleural malignant lymphoma with no history of pyothorax.