Nucleophosmin (NPM1)–mutated acute myeloid leukemia (AML) is generally associated with a favorable prognosis but demonstrates a recognized tendency for extramedullary involvement, particularly in monocytic subtypes. We report a rare case of clinically isolated gingival relapse in a patient with NPM1‐mutated AML who remained in bone marrow remission despite concurrent molecular progression. Seven months following the completion of consolidation chemotherapy, the patient developed localized gingival enlargement in the absence of cytopenias or morphological marrow relapse. Gingival biopsy confirmed leukemic infiltration with NPM1‐mutated blasts, prompting salvage therapy and subsequent allogeneic stem cell transplantation, with regression of the oral lesion. This case highlights the potential discordance between measurable residual disease and clinical relapse and underscores the oral cavity as a potential sentinel site of extramedullary disease. Vigilant intraoral examination and prompt biopsy of atypical lesions are essential for early detection of relapse in patients with AML, even during apparent remission.
Singh et al. (Thu,) studied this question.