Reactive angioendotheliomatosis in association with the antiphospholipid syndrome

A 50-year-old woman with systemic lupus erythematosus developed extensive necrotic skin lesions on her chest and abdomen after the discontinuation of warfarin. The presence of antiphospholipid antibodies suggested a diagnosis of antiphospholipid syndrome. Histopathology from a skin lesion demonstrated marked expansion of the dermal microvasculature by intravascular cellular proliferation and focal thrombosis. The intravascular cells stained positive for the endothelial cell markers CD31 and factor VIII-associated antigen confirming reactive angioendotheliomatosis (RAE). This report is the first to identify RAE occurring in the context of the antiphospholipid syndrome. We suggest that intravascular endothelial proliferation, in concert with thrombosis, contributed to the angio-occlusive pathology.