Pituitary tumors are tumors that occur in the pituitary gland, often called pituitary adenomas, and are one of the common neuroendocrine tumors, accounting for approximately 10-15% of central nervous system tumors. The vast majority of pituitary adenomas are benign tumors. Clinically, pituitary adenomas are benign tumors that grow from the anterior pituitary gland and account for about 10-12% of intracranial tumors. They usually have endocrine function. The previous classification of tumors into suspicious, eosinophilic, and alkalophilic adenomas based on the staining characteristics of the tumor cells has been replaced by a classification of tumors based on the secretory function of the cells. Currently, there is a preference for classifying pituitary adenomas as prolactin adenomas (PRL tumors), growth hormone adenomas (GH tumors), and adrenocorticotropin adenomas (ACTH tumors).