Abstract
Cryptococcus is a yeast-like fungus. Pulmonary lesions caused by Cryptococcus neoformans typically present as single or multiple nodules or infiltrative lesions in the lungs; however, endobronchial lesions are rare. A 40-year-old previously healthy Japanese man was referred to our hospital due to an abnormality detected on chest computed tomography. The analysis revealed focal bronchiectasis and bronchial wall thickening in the right upper lobe, which persisted for 6 months. Bronchoscopy showed reddish and edematous mucosa, stenosed bronchi (right B1 and B3), and white moss at the bifurcation of the right upper bronchus. Transbronchial biopsy revealed numerous yeast-like fungi and an encapsulated body. Bronchial washing for fungus culture identified Cryptococcus neoformans. Although analysis for serum cryptococcal antigen was negative, bronchoscopy led to a definitive diagnosis. Antifungal treatment improved the bronchial wall thickening. This is a rare case of endobronchial cryptococcosis caused by Cryptococcus neoformans without pulmonary parenchymal involvement in an immunocompetent host.