Reappearance of acute myeloid leukemia after almost 23 years of continuous complete remission

Despite major advances in the treatment of acute myeloid leukemia (AML) in adults over the last 3 decades, most patients with other than acute promyelocytic leukemia (APL) still succumb to the disease. For young adults (<60 years of age), death during initial treatment has become the exception rather than the rule it once was, primarily due to major improvements in supportive care, and approximately 70% will achieve a complete remission (CR) with appropriate treatment. However, even among young adults with non-APL AML, only about 25% are cured with present-day therapy, and most relapse and die well within several years of obtaining a first CR. Relapse is usually assumed to be the result of subclinical disease that persisted throughout initial treatment. However, occasional reports of very late relapses of AML suggest that other mechanisms, such as the development of a secondary leukemia may be operative in at least some patients. We report here an extremely late reappearance of AML and discuss the implications of this observation.