Step-by-step approach to the suprasellar region. The bone of the planum sphenoidale is being removed after four osteotomies have been completed: on each side parallel and just superior to the optic canal, anteriorly just posterior to the cribriform plate and posterior ethmoidal arteries, and posteriorly at the level of the limbus of the sphenoid. Removal of the planum sphenoidale is required for obtaining adequate access to the anterior extension in tuberculum sella meningioma cases. It is not necessary, however, to remove the planum sphenoidale for strictly suprasellar tumors, such as most craniopharyngiomas. (Image courtesy of JC Fernandez-Miranda)