Bronchiolitis obliterans organizing pneumonia (BOOP) in a case of smouldering adult T-cell leukaemia

Although various respiratory diseases have been reported in human T lymphotropic virus type-1 (HTLV-1) carriers or patients with adult T-cell leukaemia (ATL), there appears to be no report of the development of bronchiolitis obliterans organizing pneumonia (BOOP) in ATL or HTLV-1-related disorders. We describe a 51-year-old male with smouldering ATL who developed BOOP during a long-term follow up. Bronchoalveolar lavage (BAL) and transbronchial lung biopsy (TBLB) were performed in the right lower lobe B6 with infiltrative shadows. As a result of flow cytometric analysis of peripheral lymphocytes and BAL lymphocytes, histological examination of the biopsied lung specimen, and the clinical course, we excluded the pulmonary infiltration of ATL cells and bacterial infection. Thus, he was diagnosed as having BOOP and successfully treated with corticosteroid therapy. This is probably the first report of BOOP developing in ATL. Bronchiolitis obliterans organizing pneumonia should be considered in the differential diagnosis of pulmonary complications in HTLV-1 carriers or ATL patients since BOOP can be successfully treated by corticosteroids.