Myeloid Sarcoma: Novel Advances Regarding Molecular Pathogenesis, Presentation and Therapeutic Options

Myeloid sarcoma (MS), an extramedullary form of acute myeloid leukemia (AML) is a rare tumor mass of myeloid blasts. It can disseminate to any one or multiple anatomical sites, with (synchronous MS) or without (isolated MS) bone marrow (BM) involvement. The aim of this review is to describe the most recent advances in MS regarding diagnosis, molecular background, various clinical manifestations from several organs, and treatment approaches. Due to the lack of prospective, randomized clinical trials, therapeutic decisions are a challenge for the clinician. In the era of novel targeted AML treatments, a critical analysis of how to decide the best option for individual patients, also covering the possible central nervous system (CNS) prophylaxis is provided. For the majority of the patients, AML induction chemotherapy, followed by hematopoietic stem cell transplantation (HSCT) is generally recommended. This paper discusses the role of radiotherapy, the treatment of refractory and relapsed disease, along with the therapeutic approach of difficult-to-treat patients, due to specific problems related to different anatomical sites of MS.