Microanatomy, Pathology and Surgical Strategy of Hypothalamic/Pituitary Tumors

Here we explain the microsurgical anatomy, pathology, and surgical strategies required for hypothalamic/pituitary tumor surgery. Microsurgical dissection of the superior hypophyseal artery is required for this operation. This artery originates as the main trunk from the medial part near the internal carotid artery dural ring and branches thereafter. Blood circulation disorders are unlikely to occur because an anastomosis forms on the pituitary stalk side, but the branch that reaches the optic nerve is blind and vulnerable to blood circulation disorders, requiring care. The pseudo-capsule of a pituitary tumor is pathologically formed by collagen fibers and reticulin fibers. However, this pseudo-capsule cannot be identified in all pituitary tumors. In the case of functional pituitary tumors, it is necessary to remove as much of this pseudo-capsule as possible to achieve a clinical cure; however, in the case of nonfunctional pituitary tumors, it is difficult to confirm the presence of the pseudo-capsule, increasing the risk of pituitary hypofunction and cerebrospinal fluid leakage.