[Idiopathic mediastinal and subcutaneous emphysema in a patient with acute lymphocytic leukemia after allogeneic bone marrow transplantation].

A 45-year-old man was diagnosed as having Ph1+ acute lymphocytic leukemia (ALL) in February 1997. Complete remission was achieved by chemotherapy. Allogeneic BMT from his HLA-identical sister was performed on June 11, 1997. Engraftment was relatively quick, but acute GVHD (grade I) developed. The patient was discharged on day 113. Seven months after BMT, in January 1998, exertional dyspnea developed gradually. Chest X-ray examination showed diffuse interstitial pneumonia, for which corticosteroid was started immediately. The symptoms and signs gradually improved. However, on the 20th hospital day (February 23), bilateral subcutaneous emphysema developed in the neck and supraclavicular region. Chest X-ray and CT examinations showed pneumomediastinum without pneumothorax. The pneumomediastinum and subcutaneous emphysema gradually subsided after 3 weeks of bed rest. Subcutaneous emphysema and pneumomediastinum are relatively rare complications of allogeneic BMT.