IL17A and myeloid sarcoma: The elevation of IL-6, IL-17A, APRIL, BAFF, and CD40L levels in CSF was associated with the absence of at least one of the following three radiological findings: 1: an ovoid lesion, 2: PV ≥ 3, and 3: a nodular and/or ring-shaped CE lesion, which are considered typical of MS in terms of the lesion morphology, distribution, and contrast-enhancement pattern on conventional MRI sequences (2, 3, 16, 17).