Juvenile astrocytomas with subarachnoid spread.

The surgical and necropsy findings in five cases of extracerebellar astrocytoma showing subarachnoid spread and invasion of surrounding structures are presented. The patients varied in age from 6 to 23 yr, and all died of the effects of the tumour within 20 mth of the onset of the symptoms. In each case histological examination reveals areas of piloid astrocytes, but these show varying degrees of nuclear abnormalities. Oligodendrocytomatous foci are also seen in some cases. It is suggested that nuclear pleomorphism or oligodendrocytomatous areas indicate a poor prognosis in an otherwise typical juvenile astrocytoma, and may be associated with a partly anaplastic tumour.