Acute promyelocytic leukemia with a novel TTMV::RARA fusion initially presenting as vertebral myeloid sarcoma: a case report

This report presents a rare adult case of TTMV::RARA acute promyelocytic leukemia presenting as vertebral myeloid sarcoma. Whole-transcriptome sequencing was essential for diagnosis after routine molecular tests were negative, highlighting the importance of considering rare RARA fusions in APL-like cases lacking PML::RARA. TTMV::RARA APL may be sensitive to ATRA/ATO-based therapy; however, the patient discontinued treatment. Further cases and clinical experience are needed to optimize management strategies for this rare APL subtype.