Self-Limited Primary Cutaneous Rosai-Dorfman Disease: A Case Report and Literature Review.

Rosai-Dorfman disease (RDD), also known as sinus histiocytosis with massive lymphadenopathy (SHML), is a rare, benign, and self-limiting disease. Cutaneous Rosai-Dorfman disease (CRDD) is an exceedingly rare extranodal variant, which is strictly limited to the skin and is easily misdiagnosed. We present the case of a 47-year-old Chinese woman with primary CRDD and a review of relevant literature. The patient had red-yellow papules on her left cheek and chest for more than three months with occasional tenderness. Histopathology showed phagocytic histiocytes in the dermis with the typical presentation of emperipolesis. Immunohistochemistry (IHC) staining showed S100 (+), CD68 (+), and CD1a (-). Based on these findings and the negative systemic presentation, the patient was diagnosed with primary papulonodular-type CRDD, and no treatment regimen was initiated. After three months, the skin lesions partially disappeared, confirming the spontaneous regression of CRDD.