Acute myeloid leukaemia developing in a patient with longstanding untreated chronic lymphocytic leukaemia.

A patient with chronic lymphocytic leukaemia untreated for 5 years subsequently developed acute myeloid leukaemia. It is suggested that reduced immunocompetence is the likely mechanism in this case and may also be a contributory factor in those cases which have been ascribed to the use of alkylating agents or radiation.