Metastatic clival chordoma: a case report of multiple extraneural metastases following resection and proton beam radiotherapy in a 5-year old boy.

The authors report the case of a 5-year-old boy in whom extraneural metastases developed 5 years after he underwent an occipitocervical fusion and transoral approach to treat a clival chordoma without local recurrence. Following primary resection, the patient's postoperative course was complicated by recurrent meningitis secondary to CSF leak, which responded to antibiotics, and communicating hydrocephalus, for which a ventriculoperitoneal shunt was placed. The patient then underwent postoperative proton beam radiotherapy. Five years following his initial presentation, surveillance imaging revealed a new asymptomatic lung mass for which the patient underwent thoracotomy and resection of the mass. Histological examination of the lung mass revealed findings consistent with a de-differentiated chordoma, confirming extraneural metastasis from the original tumor without evidence of local recurrence. Chest wall and scalp metastases subsequently developed, and the patient was started on an adjuvant chemotherapy regimen that included imatinib and rapamycin followed by subsequent nivolumab and an EZH2 inhibitor for recurrent, disseminated disease. Despite this patient's remote and distant metastases, primary gross-total resection for chordoma remains a critical treatment objective, followed by proton beam radiotherapy. This case illustrates the importance of interval posttreatment imaging and the emerging potential to treat chordoma with molecularly targeted therapies.