Extra-marrow relapse of leukemia is defined as evidence of leukemic cell infiltration found in tissues or organs other than the bone marrow when the leukemia patient is still in complete remission on bone marrow examination.
- Extra-marrow relapses are commonly found in the central nervous system, the reproductive system (e.g., male testes, female ovaries), or skin infiltrates such as green tumors.
- Extra-medullary relapses can be isolated, but extramedullary relapses are often a precursor symptom to a full-blown relapse of leukemia.
- The occurrence of extramedullary relapse is associated with a variety of factors, including the patient’s age, the type of leukemia they have, extramedullary involvement before treatment, and cytogenetic abnormalities.
- Patients with independent extramedullary relapse usually have a longer survival than patients with combined myeloid relapse or myeloid relapse alone.
Dr. Junying Wang, Department of Hematology, Shanghai Renji Hospital South Hospital, also contributed to this Q&A