They are stored for later release into the bloodstream. Adenomas are basically growths found on or within the pituitary gland. These tumors are quite common and represent about 10-15 percent of all intracranial tumors. Adenomas are by far the most common disease affecting the pituitary, and are usually found in people in their 30s or 40s. Most of these tumors can be successfully treated.
Pituitary tumors can vary in size and behavior.
These smaller, functional adenomas are usually detected earlier because the increased levels of hormones cause abnormal changes in the body. Approximately 50 percent of pituitary adenomas are diagnosed when they are smaller than 5 mm in size. These tumors are often discovered as they produce symptoms by compressing nearby brain or cranial nerve structures. The symptoms of a pituitary tumor generally result from endocrine dysfunction. Because of its strategic location within the skull, tumors of the pituitary can compress important brain structures as they enlarge.