Primary Suprasellar Atypical Teratoma

TUMOURS histologically identical with atypical teratoma of the pineal gland and found in the suprasellar region have been called ectopic pinealoma, germinoma, and atypical teratoma. The term germinoma has been proposed by Friedman (1947) and used by Nishiyama et al. (1966) because of the morphological resemblance of these tumours to seminoma of the testis or dysgerminoma of the ovary. The term ectopic pinealoma has been used for those tumours which may be present in the mid-line structures such as the infundibulum, neurohypophysis, or quadrigeminal plate, but as cell rests of true pineal tissue have never been found there, Russell (1954) thought atypical teratoma to be a more representative term: A classification, by Kageyama and Belsky (1961), divides tumours of theinfundibular-suprasellar region into three types. One reaches the pituitary stalk and optic pathways after arising in the pineal region and metastasizing anteriorly. A second originates within the anterior part of the third ventricle and spreads to involve the optic nerves, chiasm, pituitary and hypothalamus. The last type, located primarily extra-axially, is the ectopic pinealoma of the chiasmal region. Kageyama and Belsky showed that