TTMV::RARA-positive acute promyelocytic leukemia with marrow necrosis and central nervous system involvement at disease recurrence.

Since the identification of the TTMV::RARA fusion in pediatric cases resembling acute promyelocytic leukemia (APL) by Astolfi et al. in 2021, several similar cases have been reported worldwide. In this report, we present a case of relapsed APL in an adolescent patient, who exhibited the TTMV::RARA fusion gene. This patient exhibited extensive central nervous system involvement and experienced bone marrow necrosis during disease recurrence. Despite achieving complete remission after re-induction chemotherapy, the patient experienced a rapid second relapse, highlighting the extremely aggressive nature of this subtype. These clinical manifestations contribute to the growing recognition of this rare disease.