[Clinical and radiological study of pulmonary actinomycosis].

We clinically and radiologically examined 8 patients with pulmonary actinomycosis. Their clinical features were slowly progressive, and the most commonly occurring symptom was hemoptysis. Laboratory findings disclosed elevated ESRs, a sign of chronic inflammation. Roentgenographic films showed a higher percentage of lesions in the right lung and on the dorsal side. On chest CT images, the lesions appeared as nodular or consolidated shadows with atelectasis, and spread widely over the parietal pleura in the periphery of the lung fields. The margins of the nodules were irregular, and multiple blood vessels were involved. The internal density of the nodules contained either a low attenuation region or cavity. In relation to the pleural, local pleural thickening adjacent to the nodules was identified in all patients, and the thickened areas were thin and smooth. Although it was difficult to diagnose by transbronchial lung biopsy (TBLB), granulation tissue obtained by TBLB was considered an important finding suggestive of pulmonary actinomycosis. As diagnostic procedures, repeated TBLBs appear to be effective for lesions extending into the hilar region, and video-assisted thoracoscopic surgery, for small nodular lesions located in the periphery of the lung fields.