Clinical features and outcomes of extramedullary myeloid sarcoma in the United States: analysis using a national data set

Extramedullary myeloid sarcoma (MS, also known as granulocytic sarcoma, myeloblastoma or chloroma) is a rare form (<1%) of extramedullary acute myeloid leukemia (AML) presenting without bone marrow involvement. 1 Due to the rarity of this disease, contemporary clinical data are mostly limited to small case series. 2 , 3 , 4 , 5 The prognostic factors and outcomes of extramedullary MS are unclear. Similar to AML, the current National Comprehensive Cancer Network guidelines recommend initial treatment with induction chemotherapy for all patients diagnosed with extramedullary MS. 6 In this study, we utilized the National Cancer Database (NCDB) to describe the clinical features, prognostic factors and early treatment outcomes in extramedullary MS.