AQP4 and myeloid sarcoma: The appearance of new asymptomatic (silent) T2 hyperintense lesions on interval MRI outside of relapses is a characteristic feature used in the diagnosis of MS,5 and their absence is one of the treatment goals.6 Although MRI silent lesions during attacks have been reported in both the antibody diseases7,8 and new brain interattack asymptomatic lesions have been rarely found in AQP4-NMOSD,9 the role of new brain and spinal cord silent lesions outside of relapses is unclear in MOGAD, with only a single pediatric study noting they occur in a minority of children with MOGAD.10