Radiation Therapy for Primary Cutaneous Rosai-Dorfman Disease of the Face: A Case Report Resistant to Multiple Lines of Treatment and a Literature Review.

Rosai-Dorfman disease (RDD) is a rare subtype of sinus histiocytosis, with primary cutaneous RDD (PCRDD) being an even rarer form, characterized by cutaneous lesions without systemic involvement. PCRDD presents a significant diagnostic challenge and is often resistant to conventional therapies, including surgical resection, steroids, and chemotherapy. Currently, no established management guidelines exist for this condition. Radiation therapy is emerging as a promising treatment option, especially for refractory cases involving cosmetically sensitive or difficult-to-resect areas. This case report presents a patient with treatment-resistant PCRDD affecting the face, which was refractory to multiple therapeutic approaches, including chemotherapy. The patient achieved durable remission with radiation therapy at an 18-month follow-up, highlighting the efficacy of this modality in managing resistant PCRDD and the importance of a multidisciplinary approach.