MAG and myeloid sarcoma: Complement deposition (C9neo antigen) within macrophages and on myelin sheaths, typical of pattern II MS, was present in 8/8 active biopsies, including a single biopsy characterized by an overlap of immunopattern II and pattern III, defined by a preferential loss of myelin associated glycoprotein (MAG) and oligodendrocyte apoptosis (Fig. 4j, k, m, n).