MOG and myeloid sarcoma: Importantly, however, MOG-EM and MS show a relevant phenotypic, i.e., clinical as well as radiological, overlap [3, 14]: like MS, MOG-EM follows a relapsing course in most cases [3, 6], at least in adults, and 33 and 15% of adult patients with MOG-EM meet McDonald’s and Barkhof’s criteria for MS, respectively, at least once over the course of disease [3, 14].