Differential Study of Invasive Pituitary Adenomas in the Sellar and Cavernous Sinus Regions

This study is collecting biological samples and health information from patients with pituitary tumors that have grown into the cavernous sinus (a blood-filled space at the base of the skull) to better understand why some pituitary tumors become invasive. **You may be eligible if...** - You are between 18 and 80 years old - You have been diagnosed with a pituitary tumor that has invaded the cavernous sinus - You previously signed consent to donate biological samples or health information as part of clinical care - You are willing to participate **You may NOT be eligible if...** - Your pituitary tumor has NOT grown into surrounding structures (non-invasive) - You are pregnant or breastfeeding - Your doctor determines you are not suitable for participation for other medical reasons Talk to your doctor to see if this trial is right for you.