Rosai-Dorfman syndrome.

Rosai-Dorfman syndrome is characterized by sinus histiocytosis with massive lymphadenopathy. A 25-year-old woman presented with multiple erythematous and yellowish papules on the forehead, cheeks, chin and thigh. She had massive generalized, firm, non-tender and non-matted lymphadenopathy and mild hepatomegaly. Her hemogram was normal. A skin biopsy showed collections of histiocytes with emperipolesis and plenty of plasma cells. A lymph node biopsy showed partial loss of architecture, dilated sinuses filled with histiocytes, which showed lymphocytophagocytosis, anisonucleosis and a clear cytoplasm. She was referred to an oncologist for further management.