Myeloid sarcoma (MS) is a mass-forming, extramedullary lesion composed of neoplastic myeloid blasts, with or without maturation.  It uncommonly involves the head and neck region, affecting both adult and pediatric populations. ¹  MS can present with concomitant marrow involvement by acute myeloid leukemia or other myeloid neoplasm or as a recurrence of acute myeloid leukemia; rarely patients have no prior or concurrent bone marrow disease.  ^1-3
Cytogenetic abnormalities in myeloid sarcomas arising in different sites, including the head and neck, are heterogeneous; they include monosomy 7, trisomy 8, t(8;21), inv(16),11q23/ KMT2A rearrangement, as well as complex karyotypes. ^4,5,5-7 A subset of MS, mostly in children, have normal karyotypes but harbor mutations of FLT3,ASXL, STAG,JAK2, NRAS, KRAS or NPM1. ^3,5,8