Rosai-Dorfman disease: a case report with nodal and cutaneous involvement and review of the literature.

Rosai-Dorfman disease, also known as sinus histiocytosis with massive lymphadenopathy, is a benign proliferative disorder of histiocytes with an unknown etiology. It is a rare disease characterized by overproduction and accumulation of histiocytes within lymph node sinuses and many other extranodal sites, including skin, oral and nasal cavities, respiratory tract, eyelid, and periorbital area. In this case, a 44-year-old woman with diagnosis of Rosai-Dorfman disease, with xanthelasma-like cutaneous lesions on facial area, extending to her neck and acneiform papules on her back, cervical lymph node involvement, and concomitant presence of diabetes insipidus was presented. Histopathological examination of the lesions demonstrated diffuse lymphocyte, plasmocyte, eosinophil, and sparse neutrophil infiltration, together with histiocytes showing phagocytosed inflammatory cells (emperipolesis). Histiocytes demonstrated immunoreactivity with the antibodies for CD68 and S100, whereas they were negative for CD1a and Langerin. Laboratory tests were normal, except mild immunoglobulin G hypergammaglobulinemia. Systemic methylprednisolone therapy was effective for cutaneous lesions.