ABSTRACT
The most common lesions affecting the sellar region are pituitary non-secreting or secreting adenomas. They occur in 10" to 15" of the general population and are sometimes diagnosed incidentally. They typically occur in the third to fourth decades of life and in both sexes equally. Several pituitary selective oncogenes, tumor suppressor genes, and mediators of the pituitary cell cycle are involved in pituitary tumorigenesis. The sellar region is at the center of the cranial base and hosts the pituitary gland. Its boundaries are the optic nerves, chiasm, and circle of Willis, above; the cavernous sinuses and internal carotid arteries, laterally; and the brainstem and basilar artery, behind. The nasal cavity provides access to this space, because the sphenoid bone connects it to the pituitary gland above. The carotid arteries are in close relationship to the sphenoid bone, creating an impression in the lateral wall of the sphenoid sinus.
