Pediatric follicular bronchiolitis with severe atelectasis: a case report.

Follicular bronchiolitis is a rare pulmonary disorder characterized by the presence of multiple hyperplastic lymphoid follicles with a peribronchiolar distribution. An 11-year-old girl with total atelectasis of the right middle lobe (RML) and diffuse multiple small nodules at both lung bases presented to our hospital with frequent upper respiratory infections and pneumonia. The disease progressed during a 3-month period of macrolide therapy, and thoracoscopic biopsy with lobectomy of the atelectatic RML was performed. The histopathologic diagnosis was follicular bronchiolitis. The patient's pulmonary function improved dramatically after oral steroid treatment. It can be difficult to diagnose follicular bronchiolitis based solely on clinical, laboratory, and radiologic findings; the disorder must be confirmed histopathologically. A patient with longstanding irreversible atelectasis and resulting recurrent respiratory infection may require lobectomy for the diagnosis and treatment of follicular bronchiolitis.