Follicular bronchitis/bronchiolitis.

Nineteen open lung biopsies demonstrating follicular bronchitis/bronchiolitis were reviewed with special attention to clinical manifestations. Morphologically, follicular bronchitis/bronchiolitis was represented by coalescent reactive germinal centers adjacent to airways in the absence of clinical or pathologic evidence of chronic obstructive pulmonary disease or bronchiectasis. Three clinicopathologic groups were identified: 1) patients with collagen vascular diseases, especially rheumatoid arthritis and Sjögren's syndrome; 2) patients with a familial form of the disease or with immunodeficiency syndromes; and 3) a heterogeneous group of patients with frequent peripheral blood eosinophilia, suggesting a hypersensitivity reaction. Prognosis was related to age at the time of biopsy and, to some extent, to the clinical group. Steroid therapy had inconsistent effects in all groups identified. The differential diagnosis of lymphoid lesions in the lung is also discussed.