Isolated pulmonary leukemic relapse following successful bone marrow transplant in a child with acute lymphoblastic leukemia.

Leukemic relapse and interstitial pneumonitis are common complications for leukemic patients following bone marrow transplantation. We present the case of a successful bone marrow transplantation patient who developed an interstitial infiltrate on chest roentgenogram 212 days post-transplant that was diagnosed by open lung biopsy and found to be a leukemic relapse of the lung parenchyma. No extrapulmonary sites were involved and the infiltrate cleared in three weeks with systemic chemotherapy. Pulmonary function tests continued to demonstrate restrictive disease. The patient remained in remission for nine months following pulmonary relapse on systemic chemotherapy. This patient illustrates an unusual site of leukemic relapse and the importance of open lung biopsy in the diagnosis of the immunosuppressed patient with a pulmonary infiltrate.