CEREBELLAR ASTROCYTOMA AND RESULTING HYDROCEPHALUS
This 7 year old girl was normal until 16 months old when it was noticed that she began to fall over and that her lower limbs were stiff with a tendency to walk on the toes. At the age of 2 years there was a marked increase in the size of the head. About this time she became bed-ridden. For 3 years prior to admission patient was incontinent and for 2 years there had been repeated vomiting attacks. Examination revealed a hydrocephalic child with bilateral pyramidal tract signs, especially on the left. There was mental retardation. A posterior fossa craniotomy was performed but the patient deteriorated and died.
The specimen is of a mid-sagittal section of brain. A large rounded cyst 6 cm in diameter has largely replaced the cerebellum and has displaced the brain stem downwards. There is gross distension of the third and lateral ventricles, and the septum pellucidum has disappeared. The cyst wall is partly smooth and partly nodular. It is brownish in colour and has several small white spots 1-2 mm in diameter on the lateral wall and rusty staining on the floor of the cyst. There is ovoid opening in the posterio-lateral wall of the cyst which communicates with a similar lesion in the opposite hemisphere of the cerebellum. There apepars to be no invasion of the surrounding brain substance. Histological examination showed the nodular areas to be typical fibrillary astrocytoma and the smooth areas to be composed of flattened glial tissue only.