Diffuse dermal angiomatosis: a variant of reactive cutaneous angioendotheliomatosis.

Reactive angioendotheliomatosis (RA) is a rare, benign disease. Affected patients present with self-limited, erythematous to violaceous plaques. The clinical lesions are due to intravascular hyperplasia of cytologically banal endothelial cells in the dermis. We report 2 patients who presented with ulcerated, violaceous plaques on the lower extremities. Both had severe peripheral vascular atherosclerotic disease requiring bypass grafts. Unlike previously described cases of RA, our patient's lesions were due to a diffuse proliferation of endothelial cells in the reticular dermis with only minimal, focal intravascular proliferation of these cells. Positive immunostaining with antibodies to Factor VIII-related and CD34 antigens adds evidence that the proliferated cells in the dermis were endothelial cells.