Myeloid sarcoma at unusual sites masquerading as non-Hodgkin lymphoma: Report of two cases

Myeloid sarcoma (MS) is a rare extramedullary tumor composed of immature myeloid cells that may present de novo , concurrently with, or as a relapse of acute myeloid leukemia (AML). Uncommon anatomical presentations may clinically mimic lymphomas or other malignancies, leading to diagnostic delays. We report two unusual presentations of MS: (1) A young male with a large anterior mediastinal mass with peripheral blood and bone marrow evidence of AML and (2) a young male with ileal MS initially misdiagnosed as non-Hodgkin lymphoma and later progressing to AML. Both cases highlight the importance of high clinical suspicion, detailed histopathology, comprehensive immunohistochemistry, and bone marrow/flow cytometric evaluation for accurate diagnosis and timely management.