Pituitary Adenomas Invading the Sphenoid Sinus

Although pituitary adenomas are usually histologically benign, they sometimes invade surrounding structures. Inferior extension, especially the sphenoid sinus invasion, is not common. Such adenomas seem to cause special problems particularly in terms of treatment.

Our four patients are all women, ages 40 to 70 years old, one with a TSH-secreting adenoma, one with a prolactinoma, and two with nonfunctioning adenomas. In all four cases, the adenomas aggressively invaded the sphenoid sinus and occasionally extended further, destroying adjacent bones. All the cases were operated via trans-sphenoidal approach. Radiation therapy was done in three cases postoperatively, because these bony structures were so roughened by tumor infiltration that we were not confident we had achieved total removal, even though no tumor was left behind macroscopically. In addition, the invasion of adenomas into the dura mater was verified in all the cases. Three out of four cases that were treated with postoperative radiation therapy have so far been symptom-free and showed no tumor recurrence.

In conclusion, the best treatment at present for pituitary adenoma widely invading the sphenoid sinus is to remove the tumor as much as possible via the trans-sphenoidal approach and to augment with postoperative radiotherapy.