Neutropenic Tonsillar Ulcer as the Initial Presentation of Acute Myeloid Leukemia in a Young Woman: A Case Report

Neutropenic ulceration can represent the initial presentation of acute myeloid leukemia (AML), but diagnostic delay may occur when recurrent oral ulcers in young adults are attributed to benign causes. We report a case that highlights the diagnostic challenges posed by neutropenic oral ulceration as the first manifestation of AML. A 25-year-old woman with recurrent oral ulcers presented with severe throat pain persisting for one month despite prior cauterization and antiviral therapy. Examination revealed a large tonsillar ulcer measuring approximately 4 × 4 cm. Initial investigations demonstrated severe neutropenia (absolute neutrophil count 0.27 × 10⁹/L) with evolving pancytopenia on serial testing, with a background of mild neutropenia documented months before presentation. Initial peripheral blood flow cytometry was non-diagnostic, showing granulocytopenia with relative monocytosis and no definitive clonal features. The patient developed febrile neutropenia and was treated with broad-spectrum antibiotics and supportive care. Given persistent severe neutropenia with progressive pancytopenia despite supportive management and a non-diagnostic initial flow cytometry, repeat flow cytometry four weeks later detected circulating myeloid blasts (7.7%) with an abnormal immunophenotype. Bone marrow examination confirmed AML with monocytic differentiation, demonstrating markedly hypercellular marrow with >70% blasts and occasional Auer rods. Oral manifestations of AML, including ulceration, mucosal bleeding, and gingival involvement, may be presenting features, particularly in monocytic subtypes, and neutropenic ulceration may rarely be the dominant initial manifestation in young adults. This case underscores the importance of comprehensive hematologic screening in patients with persistent oral ulcers, particularly when accompanied by progressive neutropenia or refractory ulceration. Neutropenic ulceration should prompt systematic evaluation for underlying bone marrow disorders. Serial hematologic monitoring, with repeat flow cytometry and/or bone marrow evaluation, is warranted when initial studies are non-diagnostic. Early recognition and structured diagnostic pathways may reduce diagnostic delay and improve outcomes.