Cavum septum pellucidum: a feasible route to third ventricle.

Tumors located within the third ventricle have some potential limitations during surgical approach. Generally speaking, it is impossible to reach the third ventricle without incision of any neural structure. We report a patient with choroid glioma in the anterior part of the third ventricle, and coincident cavum septum pellucidum (CSP) in whom we could remove the tumor gross totally without damaging any neurovascular structures. The tumor expanded the space between the rostrum of the corpus callosum and the column of the fornix and lifted up the floor of CSP. The transcavum-septum-pellucidum approach anterior to foramen of Monro was chosen to remove the anterior third ventricle tumor. We propose that the tumor had likely expanded within the above-mentioned space and elevated the floor of CSP thus increasing the anteroposterior diameter of the floor providing a feasible avenue to third ventricle making it feasible to pass through the enlarged space safely. Overall, cavum septum pellucidum provided a feasible route to approach the anterior third ventricle directly.