Follicular bronchiolitis is a bronchiolar lesion characterized by the presence of hyperplastic lymphoid follicles with reactive germinal centers distributed along bronchovascular bundles. This disorder can be idiopathic or occur in association with systemic disorders such as connective tissue diseases or immunodeficiency syndromes. Relatively little is known regarding prognostic implications and treatment of this disorder.
We conducted a computer-assisted search of the Mayo Clinic database to identify cases of follicular bronchiolitis seen in adults (21 years of age or older) at our institution over a 9-year period, January 1, 1996 through December 31, 2004. Twelve patients were identified; relevant medical records and imaging studies were reviewed.
The median range of these 12 patients was 54.5 years (range, 33-81 years) and included 4 men. Four patients had a smoking history and included 3 current smokers. Most patients presented with cough and/or exertional dyspnea. Six patients (50%) manifested crackles but no digital clubbing was observed. The histopathologic diagnosis of follicular bronchiolitis had been obtained by surgical lung biopsy in 11 patients (92%) and by bronchoscopic biopsy in one. Associated histopathologic findings included granulomas (2 cases), nonspecific interstitial pneumonia (1 case), usual interstitial pneumonia (1 case), patchy desquamative interstitial pneumonia (1 case), and carcinoid tumorlets (1 case). CT findings were variable and included nodules, ground-glass opacities, consolidation, and linear opacities. Pulmonary function findings were similarly variable. Underlying disorders included Sjögren’s syndrome (1 patient), common variable immunodeficiency syndrome (1 patient), and bronchiectasis (1 patient). Six other patients had an elevated antinuclear antibody titer or rheumatoid factor. Most patients were treated with prednisone ± azathioprine with generally favorable response.
Follicular bronchiolitis is an uncommon form of bronchiolar lesions that can be idiopathic or occur in association with connective-tissue disorders, immunodeficiency syndromes, or ill-defined hypersensitivity reactions. This disorder is associated with variable findings on pulmonary function testing and CT scan.
Corticosteroid therapy appears to be beneficial in the management of follicular bronchiolitis for most patients.
Michelle Aerni, None.