Diagnosis and Management of Extranodal Rosai-Dorfman Disease Isolated to the Thoracic Spine: Systematic Review and Illustrative Case

ABSTRACT Background Rosai-Dorfman Disease (RDD) is a rare histiocytic disorder typically affecting lymph nodes. Extranodal RDD is uncommon, and isolated central nervous system (CNS) or spinal disease is particularly rare, limiting guidance on diagnosis and management. Methods We report a patient treated at our institution and conducted a systematic review of all published cases of extranodal RDD isolated to the thoracic spine. Patient demographics, clinical presentation, imaging and histopathologic findings, treatments, and outcomes were extracted. Results A 21-year-old woman presented with progressive back pain and bilateral lower extremity paresthesia. MRI revealed an enhancing extradural lesion at T3 causing spinal cord compression. Surgical resection confirmed RDD. Despite postoperative steroids and radiotherapy, recurrence occurred within months, necessitating repeat surgery. Subsequent imaging revealed further progression with unresectable extension. She was treated with corticosteroids and cobimetinib, resulting in gradual radiographic and symptomatic improvement. Our review identified 41 cases of thoracic spinal RDD, including this case. Most patients were male (80%) with median age of 40 years. Common symptoms included lower extremity weakness (83%) and sensory deficits (64%). Lesions were typically T1 isointense and contrast-enhancing. Histopathology consistently showed S100+ and CD68+ histiocytes with emperipolesis. Surgical resection was the primary treatment (98%). Despite recurrence in 21% of cases, all patients showed clinical improvement at last follow-up. Conclusions Thoracic spinal RDD is a rare and diagnostically challenging entity requiring multimodal treatment. Surgical decompression remains the mainstay of therapy for cord compression, while adjunctive medical treatments—including corticosteroids, radiation, and targeted agents—may be necessary for long-term disease control.