Description
		
The specimen consists of slices from the cerebrum and cerebellum. In the upper specimen there 
is pronounced dilatation of both lateral ventricles with thinning and fenestrationof the septum 
pellucidum. In the lower slice there is pronounced dilatation of the fourth ventricle. 
		 History
		
This 60 year old man was diagnosed with small cell carcinoma of the lung and treated 
with chemotherapy and radiotherapy. He represented 10 months later with bilateral 
papilloedema and bilateral lower limb weakness. On admission a C.T. scan showed 
communicating hydrocephalus. Microscopic examination of the brain showed numerous deposits 
of small cell carcinoma within the medulla, cerebellum and hippocampus.