Clinicopathological study of migratory lung infiltrates.

Clinical features and the histological appearances of transbronchial lung biopsy specimens were investigated in 11 patients with migratory infiltrates on the chest radiograph. Serum circulating immune complexes were increased at the time that infiltrates were present in all patients and the levels returned to normal as patients recovered clinically and radiologically. The Mantoux test response was negative in most patients. Fifty serial sections were obtained from each paraffin embedded biopsy specimen block and every 10th section was stained (step sectioning) with haematoxylin and eosin. Six patients (group 1) did not have eosinophilic infiltration; four of these had granulation tissue plugs within respiratory bronchioles when the tissue was examined by step sectioning. All had organising pneumonia and interstitial inflammation in the setting of a clinical picture consistent with bronchiolitis obliterans organising pneumonia. In two cases IgG had been deposited in intraalveolar macrophages. Biopsy specimens in five patients (group 2) showed eosinophilic infiltration; four patients had chronic eosinophilic pneumonia and one the Churg-Strauss syndrome. Step sectioning of transbronchial biopsy specimens in patients with migratory pulmonary infiltrates is useful and may support the diagnosis of bronchiolitis obliterans organising pneumonia.