Allergic bronchopulmonary aspergillosis with repeated isolation of nontuberculous mycobacteria

A 68-year-old woman without asthma presented with a cough and abnormal shadows on a chest X-ray. Computed tomography showed right middle lobe atelectasis and centrilobular nodules with a tree-in-bud appearance in the other lobes. The patient's sputum repeatedly yielded positive cultures of nontuberculous mycobacteria (NTM); however, no fungi were detected. A transbronchial biopsy showed allergic mucin with eosinophils, although the findings were not diagnostic. We suspected that the patient had pulmonary mycobacteriosis; however, treatment for this condition failed. We then performed thoracoscopy for further evaluation and treatment of the NTM infection. The resected specimen obtained from the right middle lobe exhibited the characteristic findings of allergic bronchopulmonary mycosis without evidence of mycobacterial infection. The administration of corticosteroids and itraconazole resulted in improvement of the patient's condition. The NTM appeared to be simply a coincidental colonization of the resected middle lobe bronchus. The absence of asthma, the inability to isolate fungi and the repeated isolation of NTM made it difficult to differentiate allergic bronchopulmonary aspergillosis from NTM infection.