Interstitial lung disease--an underdiagnosed side effect of chlorambucil?

A case of recurrent interstitial pneumonia following re-exposure to chlorambucil therapy for chronic lymphocytic leukemia is presented. Chlorambucil is a rare cause of pulmonary disease. The onset of symptoms may occur after only some weeks or after up to several years with no dose-response relationship. Therapy involves the discontinuation of the offending drug and the administration of steroids. The prognosis is poor, with a mortality greater than 50%.