Microvasculitis in diabetic and non-diabetic lumbosacral radiculoplexus neuropathy

Changes characteristic of microvasculitis in non-diabetic lumbosacral radiculoplexus neuropathy (left column) and in diabetic lumbosacral radiculoplexus neuropathy (right column). Upper panels: mononuclear cell infiltration of the vessel walls with separation of mural elements (hematoxylin and eosin stain). Middle panels: fibrinoid necrosis of the walls of subperineurial microvessels associated with mononuclear cell infiltration. Although occasionally found, fibrinoid necrosis of vessel walls is not typical of these conditions, presumably because of the small size of the vessels involved. Lower panels: mononuclear cells reacted to leukocyte common antigen (CD45) infiltrate the walls of epineurial microvessels. Note the close similarity of the findings of the diabetic and the non-diabetic conditions. (Dyck PJ, Windebank AJ. Diabetic and nondiabetic lumbosacral radiculoplexus neuropathies: new insights into pathophysiology and treatment. Muscle Nerve 2002;25:477-91. Reprinted with permission of John Wiley & Sons, Inc.)