[Purely cutaneous Rosai-Dorfman disease].

Sinus histiocytosis with massive lymphadenopathy or Rosai-Dorfman disease is a non-Langerhans cell histiocytosis of unknown etiolosy. The most characteristic feature is lymphadenopathy, especially that of cervical lymph nodes. In approximately 40% of patients there are extranodal manifestations of the disease. Skin is the most commonly affected organ (27%). We report a 79-year-old female patient with purely cutaneous manifestations. This form of the disease is a very rare differential diagnosis in dermatology.