[Pseudoneoplastic forms of bronchiolitis obliterans with organizing pneumopathy (BOOP)]

Chronic obstructive bronchiolitis with organizing lung disease is an anatomoradioclinical entity characterized by nonspecific inflammation associated with recurrent migratory minimally dense alveolar opacities on the chest x-ray poorly responsive to corticosteroid therapy. Excepting this typical presentation, other clinical forms may occur. We report the cases of two patients with an exceptional localized presentation raising the differential diagnosis of lung cancer.