Endoscopic Endonasal Skull Base Rosai-Dorfman Disease Biopsy and Orbital Decompression: A Case Report

 

Rosai-Dorfman disease (RDD) is a rare, benign histiocytosis disorder with only ∼100 reported cases in the literature. Even less common is skull base involvement of RDD, with only 41 reported cases. Radiographically, RDD can appear very similar to a meningioma, and RDD can only be diagnosed with tissue biopsy. This “benign” condition can cause significant neurologic morbidity both from the disease and unnecessary surgical treatment of the disease. Although rare, generally intracranial RDD has been treated with chemotherapy or radiation with limited role for surgery to relieve mass effect. Surgical approaches to the skull base are invasive and pose risk, especially for a benign and self-limiting disease like RDD. Presented, is the case of a 63-year-old woman with a presumed spheno-cavernous meningioma that was previously radiated without tissue diagnosis. In the interim, she was diagnosed with RDD by her dermatologist after skin biopsy. Upon presentation, the patient was experiencing retroorbital headaches and blurry vision, and MR imaging demonstrated progression of her lesion. On examination she had mild right proptosis and a partial Cranial Nerve III palsy. For these reasons, surgical biopsy was undertaken with the goal of orbital and optic nerve decompressions. An endoscopic endonasal unilateral approach was performed to sample tissue at the superior orbital fissure, with bony decompression of the orbit and optic canal. Her symptoms stabilized and the diagnosis was made of skull base RDD, after which she was started on steroids and methotrexate. At 1-month follow-up the patient remained well. Her proptosis improved, Cranial Nerve III symptoms remained stable, and her RDD remained stable as well. Hematology will start this patient on Cladribine for more intensive systemic therapy. This case report highlights the first use of the endoscopic endonasal approach for biopsy and symptom palliation via decompression of skull base RDD.