Myeloid sarcoma (MS), or granulocytic sarcoma, is a rare extramedullary tumor of immature myeloid cells. MS may present simultaneously with or during the course of acute myeloid leukemia (AML), myelodysplastic syndrome (MDS), or any forms of myeloproliferative neoplasms (MPN). Less commonly, it is detected as an isolated form without bone marrow (BM) involvement. Although the prognosis of MS has not been well examined due to the rarity of this disorder, it is known to be refractory to standard therapies of AML and is generally associated with a poor outcome1. Furthermore, it has been noted that patients with myeloid sarcoma have a predisposition to extramedullary relapses.