Pituitary adenomas

Pituitary adenomas are an important and frequently occurring form of intracranial tumor. They are usually benign but can give rise to severe clinical syndromes due to hormonal excess, or to visual/cranial disturbances due to mass effect. The tumor can be clinically nonfunctioning or hormone secreting. Among the latter, prolactin (PRL) and growth hormone (GH)-secreting adenomas are the most common. The majority of pituitary adenomas arise sporadically, although a subset occurs as component tumors of well-characterized familial cancer syndromes, such as multiple endocrine neoplasia type 1 (MEN1), Carney complex (CNC), and MEN1-like syndrome (MEN4).