[Pulmonary nocardiosis associated with Cushing's syndrome]

A 54-year-old man was admitted for further investigation of multiple nodules disclosed by a chest roentgenogram. Adrenocorticotropic hormone (ACTH)-dependent Cushing's syndrome was diagnosed because serum ACTH and serum cortisol levels were elevated with a loss of diurnal rhythm. Because several extensive examinations, including inferior petrosal sinus sampling, did not detest ACTH-producing tumors, the patient was also given a diagnosis of occult ectopic ACTH syndrome. The nodules disclosed on chest roentgenograms increased gradually in size and number, and some were cavitary. Bronchial secretion samples obtained by fiberoptic bronchoscopy contained numerous Nocardia asteroides bacteria. After treatment with sulfamethoxazole-trimethoprim, the nodules gradually disappeared, leaving only scars. Although mitotane had been continuously administered to inhibit the synthesis of intrinsic corticosteroids, pulmonary nocardiosis relapsed in the patient following the termination of sulfamethoxazole-trimethoprim therapy.