[A case of pulmonary nocardiosis with a polypoid lesion in a bronchus].

A 62-year-old woman was admitted with fever and bloody sputum. A mass shadow in the left S3 and obstruction of the left B3 were seen on a chest radiograph and CT. Obstructive pneumonia was suspected, and cefotiam and imipenem/cilastatin were administered. However, this treatment did not show adequate efficacy. Bronchoscopy demonstrated a yellowish-white polypoid lesion in the left B3, but histopathological findings with HE staining yielded no definite diagnosis. Subsequently, Nocardia asteroides was detected in sputum test. A sulfamethoxazole-trimethoprim combination and minocycline were administered, and the clinical findings improved. Gram-positive microfilaments were confirmed retrospectively in the pathologic specimen, and a diagnosis of pulmonary nocardiosis was made.