A risk factor  is anything that increases a person’s chance of developing a tumor. Although risk factors often influence the development of a tumor, most do not directly cause a tumor. Some people with several risk factors never develop a tumor, while others with no known risk factors do. However, knowing your risk factors and talking about them with your doctor may help you make more informed lifestyle and health care choices.
The only known risk factors for a pituitary gland tumor are the three hereditary syndromes explained below. Genetic testing  is available for these conditions.
Multiple endocrine neoplasia type 1 (MEN1) . Families with MEN1 have an increased risk of pituitary gland tumors.
Carney complex . This is another genetic condition that can increase the risk of a pituitary gland tumor.
Familial acromegaly. Acromegaly is a condition in adults that is caused by too much growth hormone. Familial acromegaly can occur as part of MEN (see above) or alone within a family.