[Minocycline-induced pneumonitis presenting as multiple ring-shaped opacities on chest CT, pathologically diagnosed bronchiolitis obliterans organizing pneumonia (BOOP)].

A 39-year old woman was admitted to our hospital because of cough and abnormal shadows on chest radiographs. She had been treated for 5 months for acne vulgaris with minocycline hydrochloride (MINO). Chest computed tomographic (CT) scans showed multiple ring-shaped opacities in both lungs. Bronchoalveolar lavage disclosed an increase in the total number of cells and a marked increase of lymphocytes. A lung specimen obtained by transbronchial lung biopsy (TBLB) was pathologically diagnosed as bronchiolitis obliterans organizing pneumonia (BOOP). Withdrawal of minocycline led to rapid remission without treatment. The clinical course and histological findings for TBLB suggested that this case was minocycline-induced BOOP. Several cases with minocycline-induced pneumonitis have been reported. However, there are few reported cases of minocycline-induced BOOP, the present case being only the second found in the literature.