Dermal mucinosis as a sign of venous insufficiency.

Dermal mucinoses are a heterogeneous group of disorders characterized by abnormal deposition of dermal mucin, an amorphous substance composed of hyaluronic acid and sulfated glycosaminoglycans. We describe two cases of dermal mucinosis in the setting of chronic venous insufficiency. Both patients presented with painful, edematous lower extremity plaques. Biopsies of all lesions showed striking dermal mucin deposition, a slight increase in small blood vessel density, slightly thickened vessel walls and no inflammation. Neither patient showed laboratory or clinical findings consistent with a secondary mucinosis such as thyroid dysfunction, lupus erythematosus, dermatomyositis, scleroderma, granuloma annulare, graft-vs.-host disease or mucin deposition post-ultraviolet or photochemotherapy treatment. Both patients were diagnosed with localized cutaneous mucinosis secondary to venous insufficiency. The clinicopathological features of this entity are described, and a pathogenic mechanism is proposed.