摘要OBIECTIVE To analyze and discuss about the clinical characteristics,pathological types,surgical modalities and techniques,and postoperative complications in children with tumor of posterior cranial fossa.METHODS Retrospective study was conducted on 102 cases of pediatric tumor of posterior cranial fossa,admitted and treated in our hospital during the period of January 1996 to January 2007.All patients underwent microscopic surgical treatment.Fiftyeight were male and 44 cases were female.The age ranged from 9months to 14 years old,with an average of 6.1±0.5 of age.Cranial CT or MRI examination was conducted before and after the surgery on all patients.RESULTS The primary manifestations for this group of patients were increased intracranial pressure and/or ataxia.Postoperative pathological diagnoses showed:46 cases of medulloblastoma,43cases of astrocytoma,11 cases of ependymoma(including 1 case of degenerative ependymoma),1 case of dermoid cvst,and 1 case of teratoma.In this group of the patients,radical surgery was used in 68 cases and subtotal surgical removal used in 31 cases,while surgical removal of large Section was performed on 3 cases.There were no deaths from surgery reported.Ninety-one cases showed significant symptomatic improvement when compared with preoperative conditions,while 11 cases showed either no improvement or more severely affected afterward.For 6 cases,postoperative ventriculoperitoneal shunt was performed within 7 days to 2 months after the surgery.Sixty-three patients gained follow-up for 3 to 60 months in duration.Thirty-nine patients regained normal life and were able to learn well,while there were 7 patients who could not live normally on their own.During the follow-up period,there were 17 cases of recurrence and 7 cases of death.In 23 cases of medulloblastoma in children with age of 3 Years old or above,2 cases who underwent surgical removal of intracranial ependymoma received small dosage of postoperative X-ray radiotherapy on the the brain and spinal cord.Nine cases of medulloblastoma in children under age of 3 and 17 cases of astrocytoma diagnosed after the surgery received chemotherapy of C:armustine.CONCLUSION Medulloblastomas and astrocytomas were the most common types of pediatric tumor of posterior cranial fossa,right followed by ependymoma,and dermoid cysts and teratomas were rare.Early correct diagnosis,proper selection of appropriate surgical modality and the surgical margin,proper treatment of postoperative complications,and the selecting right radiotherapy or chemotherapy were the key factors in influencing the prognostic outcome of children with turrtor of posterior cranial fossa.