الفهرس 
INTRODUCTION AND AIM OF TIlE WORKOnly 14 pages are availabe for public view
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Abstract
Medulloblastoma was first described in 1925 by Baiely and Cushing. Medulloblastoma is the most common malignant central nervous system tumour of childhood. The cause of this tumour is unknown.The cerebellar medulloblastoma arises in the inferior medullary velum, grows to fill the 4th ventricle and infiltrate the surrounding structures. Classically these tumours appear soft friable reddish in colour and microscopically appear as a highly cellular tumour composed of round to oval cells with little cytoplasm and hyperchromatic nuclei. Konsick et al & Plamer et al postulated that cell of origin of medulloblastoma is bipotential rest cells which may be present in the cerebrum and spinal cord. A characteristic feature of these tumours is their ability of spread via the cerebrospinal pathway into the spinal or the cerebral subarachnoid spaces. The typical clinical presentation of medulloblastoma is due to obstruction of the cerebrospinal fluid circulation leading to obstructive hydrocephalus. The patient is presented by headache, repeated vomiting blurring of vision, papilloedema, progressive increase in the head circumference (if the patient is so young and before closure of the anterior fontanelle and sutures). The features of medulloblastoma on C.T scan brain and MRl brain are sufficiently characteristic that the pathological diagnosis is suspected prior to surgery in high percentage of cases.