Figure 1 Plaques of demyelination in multiple sclerosis. (A) Active plaque containing sheets of lipid‐laden macrophages. Cellularity is particularly marked along the junction with surrounding white matter. (B) Higher magnification through the edge of an active plaque, showing sheets of macrophages and perivascular cuffs of lymphocytes. As is often the case around active plaques, the surrounding white matter is oedematous and slightly hypercellular, and the edge of the plaque quite poorly delineated. (C) Edge of a chronic active plaque. A zone of debris‐laden macrophages separates hypocellular plaque (asterisk) from myelinated white matter (top left of figure). (D) Small perivenous plaque; in isolation this appearance could cause confusion with acute‐disseminated encephalomyelitis. (E) Shadow plaque, in which myelin staining is reduced but not absent. Arrowheads indicate the edge of the plaque. (F) Chronic inactive plaque in the medulla. Note the preservation of neurones in the inferior olivary nucleus. All sections stained with luxol fast blue and cresyl violet.