Surgical Treatment of Craniopharyngioma: Transcranial Approach

Abstract

Craniopharyngiomas may develop at any point along the pituitary–hypothalamus axis, from the sella turcica to the infundibularis partes of the third ventricle but they most commonly expand in the suprasellar cistern or within the third ventricle floor [1–3]. Tumors originate from along the path of embryonic development of Rathke’s pouch out pia mater of the third ventricle. Tumors are usually classified according to the involving anatomical sites; however, large tumors may severely compress, distort, or involve neural tissue (third ventricular floor, pituitary stalk, and optic tract structures), making preoperative evaluation difficult even with excellent-quality neuroradiological studies [3–7]. In such a small area of the sellar region, therefore, accurate typing is sometimes difficult when the tumor is large. Here we propose a clinical classification system (QST classification system) based on both the tumor’s original site and the relationship of the tumor to the suprasellar membranous structures (namely the diaphragma, the arachnoid membrane, and the pia mater) [1, 6–8].