Follicular bronchiolitis: clinical and pathologic findings in six patients.

The purpose of this study was to review our experience with patients who had a definitive diagnosis of follicular bronchiolitis (FB), and to describe in detail the clinical and pathological findings, looking for common clinical aspects that may help to identify this entity. Ours is a community 750 bed teaching hospital that acts as a tertiary referral center for several subspecialties, including thoracic surgery. Six patients with a morphological diagnosis of FB, defined by the presence of coalescent germinal centers adjacent to airways, were included. Lung biopsy was obtained by thoracotomy in all patients (2 women and 4 men, mean age 53 years). In one patient FB was associated with advanced AIDS, and in another with prolonged exposure to polyethylene-flock. In 4 patients no condition previously associated with FB was found. Five patients had a history of repeated respiratory infections, 3 patients complained of dyspnea and none had peripheral blood eosinophilia. After a mean follow-up of 25 months, 2 patients responded well to steroid therapy; 3 patients suffered symptomatic exacerbations that required an increase in the steroid dose and 1 patient was not treated with steroids. The most important contribution of this series is the description of a subset of patients with FB who were not associated with other processes. These patients present relatively homogeneous clinical and pathological pictures that do not differ greatly from secondary forms.