A Case of Follicular Bronchiolitis as the Histological Counterpart to Nodular Opacities in Bronchiectatic Mycobacterium avium Complex Disease.

Here we report the case of a 72-year-old woman with nodular bronchiectatic Mycobacterium avium complex (MAC) disease. Chest computed tomography on admission revealed multiple micronodular and branching opacities in both lobes with segmental distribution; bronchiectasis and bronchial wall thickening were observed in the middle lobe and lingula. The patient consented to and underwent thoracoscopic lung biopsy; epithelioid granulomas were occasionally observed, but follicular bronchiolitis was widespread. While bronchial lesions from nontuberculous mycobacterial infection generally present as epitheliod granulomas, the present case suggests that follicular bronchiolitis can also be a histological counterpart to nodular opacities in nodular bronchiectatic MAC disease.