胸腔鏡下肺生検で診断された結核性胸膜炎

Tuberculous Pleurisy Diagnosed by Thoracoscopic Lung Biopsy

結核性胸膜炎の確定診断には胸水や胸膜生検材料からの結核菌の証明が必要であるが，胸水からの結核菌検出率は20～30％と高くなく，胸膜生検の有用性が高いことが知られている．なかでも胸腔鏡を使用した胸膜生検は病変を直接確認できるため，結核診断の遅れを最小限にできる診断法として普及している．近年，わが国ではセミフレキシブル胸腔スコープによる局所麻酔下胸腔鏡が普及し，内科医による胸膜疾患診断がなされ始めてい

A 44-year-old woman was referred to our hospital with pleural effusion and unknown fever. Mycobacterium tuberculosis was not detected by culture of pleural effusion and sputum and gastric fluid. Pleural fluid was serous and exudative, and cytological examination showed no malignant cells. Computed tomography revealed a little pleural thickening of the right middle lobe and massive pleural effusion. As acute pleurisy was suspected based on the findings of imaging studies, thoracoscopy was performed under general anesthesia. Many yellowish-white, small nodules were seen on the parietal pleura, and white small nodule were seen on the visceral pleura of the right middle lobe. Mycobacterium tuberculosis was not detected by culture and polymerase chain reaction for Mycobacterium tuberculosis （TB-PCR） of parietal pleura and pleural effusion, but was detected by only culture and TB-PCR of visceral pleura, yielding a diagnosis of tuberculous pleurisy. Her symptoms improved and the right pleural effusion decreased with isoniazid （INH）, rifampicin （RFP）, ethambutol （EB） and pyrazinamide（PZA） treatment.