NCIt definition : A type of surgery in which instruments are inserted into part of the brain by going
through the nose and the sphenoid bone. Transsphenoidal surgery is used to remove
tumors of the pituitary gland.;
Alternative definition : NCI-GLOSS: A type of surgery in which instruments are inserted into part of the brain
by going through the nose and the sphenoid bone (a butterfly-shaped bone at the base
of the skull). Transsphenoidal surgery is used to remove tumors of the pituitary gland.;