Infiltrative clival pituitary adenoma of ectopic origin.

An ectopic pituitary adenoma is a rare entity that may occur in several anatomic locations, the sphenoid sinus being the most common. Many of these tumors are amenable to surgical resection by means of a transsphenoidal approach. A more aggressive surgical approach is needed to attempt resection of extensive tumors that involve the clivus and the nasopharynx. Complete resection in these areas cannot always be guaranteed or determined, necessitating postoperative radiotherapy. Many different tumors of the sphenoid sinus and skull base can resemble ectopic pituitary adenomas on radiologic assessments. Because of this, preoperative endocrine assessment is recommended.