Interstitial pneumonia (IP) is one of the major complications after bone marrow transplantation (BMT). This complication can be due to infectious agents including cytomegalovirus (CMV), Pneumocystis carinii and herpes simplex virus or can be a late consequence of total body irradiation (TBI) and/or drug toxicity. It is still unknown whether and to what extent graft versus host disease (GVHD) can involve the lung. We report a case with chronic myelocytic leukemia in whom late-onset IP was present 180 days after BMT with chronic GVHD. Lung function tests showed restrictive changes, and multiple perfusion defects were recognized in the lung scan using TcMMA. Histologic examination of the lung biopsy revealed patchy idiopathic IP with mononuclear cells, and showed initial focal thickening within medium sized arteries. CMV, Pneumocystis carinii or other infectious organisms were not identified. IP was resolved by steroid administration. IP observed in this patient should be discerned from the more common type of IP after BMT and may be a pulmonary manifestation of chronic GVHD.
