Pituitary tumors originate in the pituitary, a pea-sized gland in the brain that secretes and regulates hormones controlling many important body functions.
The pituitary is considered the “master gland” since it releases hormones into the bloodstream to act on other glands as well as directly to organs throughout the body.
Most pituitary tumors, classified as pituitary adenomas, are benign (noncancerous) and slow-growing. Although less common, some pituitary tumors are malignant (cancerous) and can spread to other parts of the body. These are classified as pituitary carcinomas, and account for less than 1% of pituitary tumors.1
Pituitary tumors are the second most common primary brain tumor, accounting for 16.2% of all primary brain tumors.1 Pituitary tumors also occur in children, accounting for 11.8% of primary brain tumors in children and adolescents.1 In 2017, an estimated 13,060 new cases were diagnosed in the United States.1
Some rare genetic conditions, like multiple endocrine neoplasia type 1 syndrome, Carney complex, and isolated familial acromegaly, may increase the risk of developing pituitary tumors.
Pituitary adenomas can vary widely in appearance and symptoms. Approximately 50% of pituitary adenomas make and secrete excess hormones, and are called functional or secretory. These tumors can be further classified by the specific hormone that is being made.
The signs and symptoms of pituitary tumors largely result from the effects of the excess hormone. Some common pituitary tumors, organized by the hormone it secretes, include the following:
- Growth hormone-secreting tumors may cause acromegaly, resulting in excess growth of hands, feet, and jaws.
- ACTH-secreting tumors may cause Cushing’s disease, affecting almost every organ in the body.
- Prolactin-secreting tumors (also called prolactinoma) may affect a woman’s menstruation or breast milk production.
- TSH-secreting tumors can cause hyperthyroidism, affecting metabolism and anxiety.
The remaining 50% of pituitary adenomas do not secrete hormones at all, making them non-functional or non-secretory. Non-functional pituitary adenomas can cause symptoms only when they become large enough to compress the optic nerves or the pituitary gland, affecting vision or hormone production, respectively. These types of symptoms can also occur when functional pituitary adenomas get large enough.
To learn more about specific pituitary tumor types and symptoms, please find information at UCSF’s California Center for Pituitary Disorders.
Incidentally found non-functional pituitary adenomas that are small enough can be kept under observation. Larger and/or symptomatic non-functional pituitary adenomas as well as functional pituitary adenomas are usually most effectively treated with surgery, to remove as much of the tumor as possible. Depending on the size and exact location of the tumor, patients with pituitary tumors may be a candidate for endonasal transsphenoidal surgery. This minimally invasive operation involves removing the tumor endoscopically, using special tools and scopes that pass through small openings – in this case, the nasal passages. Because most pituitary tumors can be removed through the patient’s nose, this type of procedure does not require drilling into the skull, or making facial or scalp incisions.
Non-functional and functional pituitary adenomas can be treated with postoperative radiation if surgery does not prove curative for a functional adenoma, or if there is concern about potential growth for a non-functional adenoma. Some functional pituitary adenomas can be treated with medical therapy to shrink the tumor should surgery fail to achieve cure. Medical therapy may also be used as an alternative to surgery for prolactinomas. Because pituitary tumors can cause hormone deficiencies, treatment may also include medical hormone replacement to address hormone-specific symptoms.
To learn more about pituitary tumor treatment, please find information about at UCSF’s California Center for Pituitary Disorders.
Recovery depends on a variety of factors, including type and size of the tumor. However, most adult and pediatric pituitary tumors can be successfully treated with surgery, and the recovery from transsphenoidal surgery is typically quick with minimal co-morbidities.
Continued care will monitor for recurrence of the pituitary tumor, as well as hormone treatment if needed.
- Ostrom, Q.T., et al., CBTRUS Statistical Report: Primary brain and other central nervous system tumors diagnosed in the United States in 2010-2014. Neuro Oncol, 2017. 19(suppl_5): p. v1-v88.