Salvage With Revumenib: Targeting KMT2A‐Rearranged Isolated Leukemia Cutis Identified in the Extramedullary Disease

ABSTRACT Acute myeloid leukemia (AML) is an aggressive hematologic malignancy associated with a high risk of relapse. Leukemia cutis is characterized by the presence of neoplastic leukocytes infiltrating the skin. Here, we present a previously treated AML patient who relapsed with isolated leukemia cutis without bone marrow involvement. Fluorescence in situ hybridization (FISH) and RNA sequencing of the skin lesion revealed a KMT2A::MLLT6 rearrangement, which enabled the use of revumenib. This case highlights the diagnostic complexity and therapeutic implications of isolated extramedullary AML relapse and underscores the need to perform genetic testing at the site of disease recurrence—especially without bone marrow involvement of relapsed disease. Trial Registration The authors have confirmed clinical trial registration is not needed for this submission.