Update on pulmonary and pleural lymphoproliferative disorders

HRCT findings of childhood follicular bronchiolitis

BACKGROUND

Follicular bronchiolitis is a lymphoproliferative form of interstitial lung disease (ILD) defined by the presence of peribronchial lymphoid follicles. Follicular bronchiolitis has been associated with viral infection, autoimmune disease and immunodeficiency. The most common clinical manifestation is respiratory distress in infancy followed by a prolonged course with gradual improvement. We found no reports of systematic review of high-resolution computed tomography (HRCT) findings in pediatric follicular bronchiolitis.

OBJECTIVE

The purpose of this study was to describe the HRCT findings of follicular bronchiolitis in children and correlate these imaging findings with histopathology.

MATERIALS AND METHODS

A 5-year retrospective review of all pathology-proven cases of follicular bronchiolitis was performed. Inclusion criteria were age <18 years and an HRCT within 6 months of lung biopsy. HRCTs were reviewed by three observers and scored using the system previously described by Brody et al.

RESULTS

Six patients met the inclusion criteria with age range at HRCT of 7-82 months (median: 39.5 months). Pulmonary nodules (n=6) were the most common HRCT finding followed by focal consolidation (n=5), bronchiectasis (n=4) and lymphadenopathy (n=3). Tree and bud opacities and nodules on CT correlated with interstitial lymphocytic infiltrates and discrete lymphoid follicles on pathology.

CONCLUSION

The salient HRCT findings of childhood follicular bronchiolitis are bilateral, lower lung zone predominant pulmonary nodules and bronchiectasis with infantile onset of symptoms. These characteristic HRCT findings help differentiate follicular bronchiolitis from other forms of infantile onset ILD.

Follicular bronchiolitis: A rare cause of persistent atelectasis in children

Although atelectasis is common in children, its persistence or refractoriness to treatment should lead prompt evaluation to identify causal mechanism. We describe the case of a child presenting in first year of life with persistent left upper lobe atelectasis, recurrent wheezing and respiratory infections refractory to medical therapy, submitted to partial lobectomy when he was 3 years old age. Histopathological examination revealed follicular bronchiolitis. Systemic underlying diseases were excluded. Clinical improvement was initially achieved using inhaled corticosteroids, but oral therapy was needed due to clinical relapse, with favorable response.

Follicular bronchiolitis, a rare pulmonary primary lymphoid lesion, consists of numerous reactive lymphoid follicles in a peribonchiolar distribution. Its precise cause is unknown, particularly in children, in which few cases have been reported. Treatment usually includes steroids and prognosis is generally good.