Pediatric ganglioglioma of the brainstem and cervicomedullary junction: a retrospective cohort study.

Ganglioglioma is a low-grade central nervous system neoplasm with a pediatric predominance, accounting for 10% of all brain tumors in children. Gangliogliomas of the cervicomedullary junction (GGCMJs) and brainstem (GGBSs) present a host of management challenges, including a significant risk of surgical morbidity. At present, understanding of the prognostic factors-including BRAF V600E status-is incomplete. Here, the authors report a single-institution GGCMJ and GGBS experience and review the pertinent literature.A prospectively maintained neurosurgical database at a large tertiary care academic referral center was retrospectively queried for cases of GGCMJ pathologically confirmed in the period from 1995 to 2015; appropriate cases were defined by diagnosis codes and keywords. Secondary supplemental chart review was conducted to confirm or capture relevant data. The primary study outcome was treatment failure as defined by evidence of radiographic recurrence or progression and/or clinical or functional decline. A review of the literature was conducted as well.Five neurosurgically managed GGBS patients were identified, and the neoplasms in 4 were classified as GGCMJ. All 5 patients were younger than 18 years old (median 15 years, range 4-16 years) and 3 (60%) were female. One patient underwent gross-total resection, 2 underwent aggressive subtotal resection (STR), and 2 underwent stereotactic biopsy only. All patients who had undergone STR or biopsy required repeat resection for tumor control or progression. Progressive disease was treated with radiotherapy in 2 patients, chemotherapy in 2, and chemoradiotherapy alone in 1. Immunostaining for BRAF V600E was positive in 3 patients (60%). All 5 patients experienced at least one major complication, including wound infection, foot drop, hemiparesis, quadriparesis, cranial neuropathy, C2-3 subluxation, syringomyelia, hydrocephalus, aspiration, and coma. Overall mortality was 20%, with 1 death observed over 11 years of follow-up.GGBS and GGCMJ are rare, benign posterior fossa tumors that carry significant perioperative morbidity. Contemporary management strategies are heterogeneous and include combinations of resection, radiotherapy, and chemotherapy. The BRAF V600E mutation is frequently observed in GGBS and GGCMJ and appears to have both prognostic and therapeutic significance with targeted biological agents.