Cerebellopontine angle tumors in infants and children

Cerebellopontine angle (CPA) and cerebellomedullary fissure (CMF) tumors are rare in children and information is scarce in the literature. This retrospective study reports their histological distribution and tumor origin, and describes surgical resections and post-operative outcome based upon the authors' consecutive personal series.

Clinical data of infants and children 16 years old or younger of age treated from 2001 to 2012 by a single surgeon was retrospectively reviewed. All had histologically verified CPA/CMF tumors and underwent radical tumor resection through craniotomy except for two children who had a stereotactic biopsy for malignant tumors (glioblastoma and primitive neuroectodermal tumor (PNET)). Tumors' pathological distributions, tumors' origin, surgical approaches, and patients' outcome were reviewed.

There were 44 infants and children with the age at diagnosis ranging from 11 weeks to 16 years; 32 were predominantly in the CPA and/or CMF whereas 12 showed an extension to the fourth ventricle. Pathology showed 14 ependymomas, 12 benign gliomas (11 pilocytic astrocytomas, 1 ganglioglioma), 4 atypical teratoid rhabdoid tumors (ATRTs), 4 epidermoids, 3 primitive neuroectodermal tumors (PNETs), 3 meningiomas, 3 nerve sheath tumors, and 1 glioblastoma. The anatomical site of tumor origin was the lateral recess of the fourth ventricle in 13 patients, the ventral cerebellar hemisphere in 8, the cerebellar peduncle in 7, and the brain stem in 6. Others were from embryonal nest, cranial nerve, or meninges. For 42 tumor resections, 38 were approached through a posterior fossa craniotomy and 4 through a temporal craniotomy and transtentorial approach. At tumor resection, 26 had a gross total or near total resection, 12 subtotal resection, and 4 partial resection. There were no mortalities. The most significant morbidity was ninth and tenth nerve palsy; 15 patients had unilateral vocal cord palsy or dysphagia. Of these, nine were treated with nasogastric (NG) feeding tube, five with a combination of gastrostomy (G-tube) and tracheotomy, and one with G-tube. All had successful removal of NG feeding from 1 month to 2 years (average 6 months). The tracheostomy and G-tube were removed between 4 months and 2 years (average 14 months) in all.

A plethora of tumor types occur in childhood at the CPA/CMF and our review indicated 50 % were benign in histology. High rates of lower cranial nerve morbidity were experienced but their dysfunctions were often recovered or compensated in 2 years. However, one should be cognizant of these complications and conduct resection with appropriate surgical approach, intraoperative monitoring, and surgical microscope.