An angiocentric IgA-kappa bilateral pulmonary lymphoma developed in a 9-year-old boy treated with chemotherapy for 3 1/2 years for acute lymphoblastic leukemia. The tumor was confined to the lungs and had extensive infarction secondary to vascular involvement. This and 2 similar reported cases suggest that compromise of the host's immune system may contribute to the development of pulmonary lymphoma in children, an uncommon site and probably labeled previously as lymphomatoid granulomatosis.