Colloid cyst of the third ventricle is a relatively rare intracranial neoplasm. If recognized and treated surgically, it offers a favorable prognosis.1 The clinical picture which such a tumor presents is not definite, but features of the history and physical signs suggest the correct diagnosis. However, the final diagnosis is dependent on the results of ventriculographic study.
Such a tumor rarely appears before the age of 20 years, and the distribution is about equal between the sexes. The duration of symptoms is variable. Dandy2 stated that in about 50 per cent of all cases the signs and symptoms are of less than one year's duration. However, in Fuller's case symptoms were present for twenty years. The clinical picture in a typical case is one of severe intermittent headaches, which are bifrontal and may occasionally be relieved by a change in position of the head. Vomiting and nausea are