pituitary tumor (pih-TOO-ih-TAYR-ee TOO-mer)
A tumor that forms in the pituitary gland. The pituitary gland is a pea-sized organ at the base of the brain. It makes hormones that affect other glands and many of the body’s functions, including growth. Symptoms depend on the hormones affected by the tumor. Most pituitary tumors are benign (not cancer) and many do not cause any symptoms.