[A case of imatinib mesylate-induced pneumonitis based on the detection of epithelioid granulomas by video-assisted thoracoscopic surgery biopsy in a patient with chronic myeloid leukemia].

A 79-year-old man with chronic myeloid leukemia was referred to our department because of dry cough and low-grade fever, 272 days after commencing imatinib mesylate (Gleevec). High resolution computed tomography (HRCT) showed tiny scattered centrilobular nodules and ground-glass opacities throughout both lung fields, suggesting drug-induced pneumonitis. A thoracic video-assisted thoracoscopic surgery (VATS) biopsy specimen from the centrilobular nodules in the right upper lobe demonstrated patchy distribution of epithelioid cell granulomas and intra-alveolar organization. Most of those lesions were predominantly located in the alveolar spaces, which implicated non-transbronchial distribution. Following drug cessation alone, the patient's general condition and radiological abnormalities improved.