Chronic cerebrospinal fluid rhinorrhea as an initial presentation of chordoma: illustrative case.

backgroundSkull base chordomas are typically extradural and present with cranial nerve deficits, headache, and visual disturbances. Clival chordoma involving the dura and presenting as a spontaneous cerebrospinal fluid (CSF) leak is extremely rare and can be mistaken for other skull base lesions. Here the authors present a case of chordoma with an unusual presentation. OBSERVATIONS: A 43-year-old female who presented with clear nasal drainage was diagnosed with CSF rhinorrhea secondary to a clival defect previously thought to be ecchordosis physaliphora. The patient subsequently developed bacterial meningitis and underwent endoscopic, endonasal, transclival gross-total resection of the lesion with repair of the dural defect. Pathology revealed brachyury-positive chordoma. She received adjuvant proton beam radiotherapy and has remained stable for 2 years. LESSONS: Spontaneous CSF rhinorrhea can occur as a rare primary presentation of clival chordoma, requiring careful radiological interpretation and a high index of suspicion for diagnosis. Chordoma cannot be reliably differentiated from benign notochordal lesions based on imaging alone; thus, intraoperative exploration and immunohistochemistry play key roles. Clival lesions presenting with CSF rhinorrhea should undergo prompt resection to facilitate diagnosis and prevent complications. Future studies on connections between chordoma and benign notochordal lesions may help to establish management guidelines.