In the early 1990s, the role of surgery in midbrain glioma was well recognized. Most midbrain gliomas grow focally, which can be divided into tectum, tegmental, and aqueduct gliomas, based on the original locations 1).
Two cases of tumor of the cerebral aqueduct are described. Case 1 is a pilocytic astrocytoma in a 16-year-old girl with a two-year history of intermittent increase of intracranial pressure. The tumor was completely confined within the lumen of the aqueduct. Case 2 is a subependymoma of a 68-year-old man. The tumor extended beyond the aqueduct to the periaqueductal gray matter and produced signs and symptoms suggesting normal pressure hydrocephalus. The literature contains 18 other cases of tumor of the aqueduct: 13 gliomas and five vascular malformations. All, except one, produced clinical manifestations of generalized hydrocephalus lasting from 20 days to six years. The result generally did not correspond to the histologic type of the tumor. Like gliomas of the brainstem in general, those in the aqueduct tend to occur in childhood and adolescence and affect male more than female patients 2).