A 27-year-old male visited the outpatient clinic of our hospital with the chief complaints of fever, right chest pain and shortness of breath. He was admitted to our hospital for detailed examination of the right hydrothorax. The pleural effusion obtained by thoracocentesis was exudative and negative for Mycobacterium tuberculosis. Since the titer of adenosine deaminase in the pleural effusion was abnormally high, antitubercular therapy was started under suspicion of tuberculous pleuritis. Thereafter, the patient's subjective symptoms and blood parameters improved. Necrotic tissues were obtained by pleural biopsy using the Cope needle. In order to make a definitive diagnosis, pleural biopsy was performed thoracoscopically. White tubercular lesions with a smooth surface were sparsely distributed on the pleura. Histopathologically, these lesions were characterized by central areas of caseous necrosis surrounded by epithelial cells and Langhans' giant cells. Therefore, they were considered to be granulomatous lesions. The patient was given a diagnosis of idiopathic tuberculous pleuritis, and was treated with four antitubercular drugs in combination. His clinical signs subsided, and he was discharged. This case indicates that the examination of the inside of the pleural cavity with a flexible bronchoscope, instead of thoracoscope, under local anesthesia is useful to diagnose patients having tuberculous pleuritis.
