An Autopsy Study about the Origin of Craniopharyngioma confined in the Third Ventricle

A case of craniopharyngioma confined to the third ventricle is reported. A 49-year-old male was admitted because of progressive memory defects. No abnormal neurological findings were present. Post-contrast axial computed tomography (CT) scan showed a large, homogeneously enhanced mass in the third ventricle. Coronal CT showed this mass separated from the sella turcica and confined in the third ventricle. The tumor was partially removed by a transcallosal approach under an operating microscope. Histologically, this tumor was a squamous cell type craniopharyngioma. The patient died of the tumor recurrence 5 months after surgery. Autopsy demonstrated that the tumor did not become exposed on the basal surface of the brain, and that no tumor was found around the hypophyseal stalk. A stalk-like structure in this tumor was found at the base of the third ventricle wall, which was considered to be the origin of the tumor. It was disclosed that this tumor was a craniopharyngioma, originating from the remnant of Rathke's pouch in the tuber cinereum, and proliferating exclusively in the third ventricle.