Long-Term Outcomes in the Treatment of Pediatric Skull Base Chordomas

Introduction: Pediatric skull base chordoma is a rare entity that is traditionally considered to display aggressive behavior and a tendency to recur. However, there is an absence of literature examining outcomes in the pediatric population. We present our center’s experience with these lesions.

Methods: We retrospectively reviewed all patients presenting up to age 18 with skull base chordomas to the University of Pittsburgh Medical Center from 2004 to 2018. The presenting symptoms, patient demographics, operative characteristics, radiographic characteristics, and clinical outcome were reviewed. The number of recurrences and progression-free survival time were determined.

Results: Sixteen patients met criteria: 9 male and 7 female patients with a mean age of 12 years (range 4–18). The most common presenting complaints were diplopia (n = 5), headache (n = 5), and swallowing difficulty (n = 4). Three cases were incidentally discovered. Four patients had recurrent tumors referred to our institution, two despite proton beam radiotherapy. One patient received standard external beam radiotherapy prior to referral for first time surgical resection. Ten patients underwent endoscopic endonasal approach (EEA) alone, four patients had combined EEA with open far lateral or extreme lateral approaches, and two patients had two-stage EEA procedures. Eleven patients had gross-total resection based on intraoperative impression and postoperative imaging; five patients had near-total resection. Ten patients had intradural tumor extension, five had interdural tumor only and one patient had a purely extradural lesion. Six patients developed cerebrospinal fluid leaks requiring re-operation, two patients developed new, permanent cranial neuropathies, one patient suffered an internal carotid injury that required carotid sacrifice and resulted in a Horner’s syndrome, one patient developed an epidural hematoma, and one patient developed a subdural empyema.

Nine patients had postoperative proton beam radiotherapy. Three (19%) patients developed tumor progression during follow-up, of which two patients had craniocervical lesions treated with a combined open far/extreme lateral approach and EEA approach (p = 0.2, Fisher’s exact). Six patients had chondroid chordomas and 10 were conventional. Two recurrences occurred in chondroid patients, and both patients had multiple recurrences (p = 0.52, Fisher’s exact). Two patients with recurrence underwent further resection, and one elected to stop treatment. Both patients suffered a second recurrence, one of which elected to stop treatment. The mean radiographic follow-up was 59 months (median: 56, range: 1–136 months). A total of 937 months of follow-up were documented, with a cumulative time to recurrence of 187 patient-months. Among the patients who developed recurrence, the mean time from resection to recurrence was 21 months (Median: 23 months, range: 1–43 months).

Conclusion: Pediatric skull base chordoma, when managed aggressively at a specialized center with a goal of gross-total resection, may have a better outcome than traditionally believed. Recurrences in approximately one fifth of patients were noted in the first few years after resection. While complications such as cerebrospinal fluid leaks were prevalent with aggressive resection, these were mostly short-term, manageable issues. Chordomas spanning the craniocervical junction and with chondroid pathology may be more prone to recurrence.