Pituitary Macroadenoma

56-year-old male with history of low testosterone and elevated prolactin levels. There is an infiltrating, FLAIR mildly hyperintense, enhancing mass invading the left cavernous sinus deep venous sulcus compartment, with greater than 90 degrees encasement of the horizontal cavernous internal carotid artery segment on the left. There is no component of the mass extending into the suprasellar compartment or displacing the infindibulum. The findings are compatible with a pituitary macroadenoma. Macroadenomas are approximately twice as common as microadenomas. Typical clinical presentations result from local mass effect on surrounding structures. Hormonally active tumors tend to be detected earlier, and larger lesions are prone to hemorrhage. Prolactin secreting lesions are more frequently seen with cavernous sinus invasion. Complete resection is difficult in the setting of cavernous sinus invasion.