Remission of hairy cell leukemia without treatment.

A patient is described with hairy cell leukemia, in whom a remission occurred spontaneously or in association with Legionnaires or subsequent HIV infection. Possible pathophysiological mechanisms are reviewed. Currently it is seventeen years since the diagnosis of hairy cell leukemia and fourteen years since the infusion of HIV infected blood. Hairy cell leukemia has yet to return and HIV infection has not progressed to AIDS.