Focal endothelial cell degeneration and proliferative endarteritis in trauma-induced early lesions of necrobiosis lipoidica diabeticorum.

Microangiopathy is an essential component in diabetic vascular pathology. We report ultrastructural observations of ballooning degeneration involving isolated endothelial cells of cutaneous capillaries, while leaving adjacent endothelial cells relatively intact in six diabetic patients with early lesions of necrobiosis lipoidica induced by trauma. Focal proliferation of endothelial cells encroaching upon the vascular lumina (obliterative endarteritis) was also observed. Lectin studies on biopsy specimens of older lesions of necrobiosis lipoidica revealed paucity of dermal blood vessels. These observations enable us to gain further insight into the pathophysiological mechanisms that underlie diabetic microvascular disease.