In the case of pituitary tumors, if the size reaches two centimeters, it is relatively large. Under normal circumstances, pituitary tumors can be classified into several types based on their size: microadenomas are generally smaller than one centimeter, macroadenomas are larger than 1.0 centimeter, and giant adenomas are larger than 3.0 centimeters. Usually, a two-centimeter pituitary tumor is already considered a macroadenoma. Normally, such large pituitary tumors often compress the surrounding pituitary tissue, causing hypofunction of the pituitary tissue and significant hormonal disturbances, which can lead to a range of uncomfortable symptoms and signs in patients.