[Hematology Reports 2015; 7:5709] [page 27]

Myeloid sarcoma (MS) is a rare disease enti-ty identified as a variety of manifestations defined by the occurrence of extramedullary myeloid cell masses with or without bone mar-row involvement. This case describes an unusu-al presentation of isolated MS in a 60-year-old otherwise healthy male, who initially presented to his primary care physician with vague abdominal pain. After extensive workup includ-ing three omental biopsies, umbilical core biop-sy, and inguinal lymph node biopsy, he was ulti-mately diagnosed with isolated MS with exten-sive extramedullary tumor burden. Despite advanced extramedullary disease, peripheral cell counts were normal and bilateral bone mar-row biopsies unremarkable with normal cellular lineages, morphology, and cytogenetics. The patient underwent induction chemotherapy and is now greater than 100 days post myeloablative unrelated donor marrow transplantation with no evidence of disease recurrence and 100% donor status with full chimerism. This case demonstrates that making a prompt diagnosis with rapid initiation of treatment in myeloid sarcoma can be challenging due to its varied clinical presentation, cytomorphology, cyto-chemistry, and cytogenetic overlap with other lymphoid malignancies. Once a diagnosis of MS has been made, moving quickly to induction therapy is important. Several studies have shown that improved overall survival is attained when MS is treated as acute myeloid leukemia and increased survival is noted for patients undergoing bone marrow transplantation. Further prospective studies are needed to eluci-date the many remaining questions in regards to the natural history, prognosis, and optimal treatment strategies for this deadly disease