This book presents todays level of knowledge about pituitary adenomas and meningiomas. Molecular biology has added significant new information to our understanding of these tumors which in turn affects the current treatment of these tumor types. Pituitary adenomas require meticulous study not only in the diagnosis, but also in the analysis of the right kind of therapy which includes surgery, radiosurgery and medical treatment. Great progress has also been achieved in research on the hormonal aspects of meningiomas. Clinical symptomatology and treatment of these tumors depend largely on the localization of these meningiomas. The special problems associated with meningiomas of the cavernous sinus differ greatly from those of ventral foramen magnum meningiomas or optic sheath meningiomas. Experts on these specialized localizations of meningiomas present their experience.