Cutaneous Rosai-Dorfman disease.

Sinus histiocytosis with massive lymphadenopathy, or Rosai-Dorfman disease, is a benign idiopathic histiocytic proliferative disorder that commonly involves the lymph nodes but secondarily may involve the skin. However, purely cutaneous disease without lymphadenopathy or internal organ involvement rarely may occur. We present case reports of three patients who presented with asymptomatic nonspecific enlarging skin nodules without evidence of lymphadenopathy or internal disease.