Pediatric Cerebellopontine Angle Tumors

ABSTRACT

From 1957 to Jun 1987, authors experienced 8 cases of pediatric brain tumor located in the cerebellopontine angle(CPA) which were operated upon at the Department of Neurosurgery of Seoul National University Hospital. The proportion of the pediatric CPA tumors in the total pediatric brain tumors was 4% (8/197), and that in the pediatric posterior fossa tumors was 8% (8/100). The pathologic diagnoses of the 8 cases were ependymoma (2 cases), medulloblastoma (2 cases), astrocytoma ( 1 case), primitive neuroectodermal tumor (1 case), trigeminal schwannoma (1 case) and Masson's hemangioendothelioma (1 case). The proportion of CPA location in the posterior fossa ependymomas was 13% (2/16), and those of the posterior fossa medulloblastomas and astrocytomas were 4% (2/50 and 1/28, respectively). The initial presentations were symptoms of increased intracranial pressure in 5 cases, and those of cranial nerve dysfunction in 3 cases. On admission, all of 8 cases showed signs of increased intracranial pressure and among the cranial nerve dysfunctions, facial nerve dysfunction was most common (5 cases). It seemed that it was due to close relationship between these tumors and fourth ventricle, and the patients' age which was too young to complain of subtle subjective sensory dysfunctions. The operative findings showed medial displacement and compression of the cerebellum, brain stem and cranial nerves, enlargement of surrounding subarachnoid space or arachnoid cyst formation, tumor growth into the cranial nerve canals, and encasement of nerves or vessels by the tumor. The sites of origin were lateral recess of fourth ventricle in 4 cases (2 ependymomas and 2 medulloblastomas), and surrounding brain tissue in the other 2 glioma cases. And a representative case was presented.