CNS relapse in a low risk acute promyelocytic leukemia patient treated with ATRA-based regimen: is there a role for prophylactic CNS therapy in acute promyelocytic leukemia?

Though the incidence of CNS relapse in acute promyelocytic leukemia (AML-M3 FAB classification) has increased following the advent of all-trans retinoic acid (ATRA), still CNS relapse accounts for only 2-3% of all relapses in AML-M3 trated with standard ATRA plus chemotherapy regimen. We report a case of low risk AML-M3 treated with standard therapy, developing CNS relapse while on maintenance therapy with ATRA + 6-mercaptopurine (6-MP) + methotrexate (MTX).