True about pilocytic astrocytoma all except aEUR'

Median age at presentation is more than 80 years Astrocytomas Histologically astrocytomas are classified into ? a) Protoplasmic or fibrillary b) Gemistocytic (enlarged cells distended with hyaline and eosinophilic material) c) Pilocytic (consists of enlarged bipolar cells) d) Mixed astrocytoma or oligodendroglioma Astrocytomas have been graded into 4 grades based on their biological behaviour (WHO grading schemes). Grading schemes for astrocytomas have clinical utility in predicting prognosis and treatment options. The tumour grade is expressed in the format X/IV. Pilocytic astrocytomas They are also called low grade astrocytomas. These are the predominant group of astrocytomas in childhood. Juvenile pilocytic astrocytoma is the most common astrocytoma in children accounting for 20% of all brain Although JPA can occur anywhere in the C.N.S. the classic site of presentation is cerebellum (posterior fossa). tumours. Microscopically it is characterized by Rosenthal fibres - compact area of condensed mass of glial filaments. Classic neuroradiological findings is the presence of contrast medium enhancing nodule within the wall of a cystic mass. JPA has low metastatic potential and is rarely invasive. JPA very rarely undergoes malignant transformation. Treatment With complete surgical resection the overall survival approaches 80-100%.