When an individual experiences the development of abnormal growth in their pituitary gland, it is referred to as a pituitary tumor. Pituitary gland tumors may be malignant and spread around the body, or they may be noncancerous. While most benign growths in the body do not cause problems when they are small in size, that is not the case with many types of pituitary tumors. The endocrine system in the body contains numerous glands that communicate and command each other to take action through the release of hormones.
A tumor that develops in the pituitary gland can cause the gland to produce an excessive amount of one or more hormones, which then causes other glands around the body to overproduce hormones. Other types of pituitary tumors can destroy the cells in the pituitary gland that produce one or more hormones, resulting in a hormone deficiency.
Nonfunctional adenomas or null cell adenomas are terms used to describe an abnormal growth in the pituitary gland that is benign but may grow to a large size. A nonfunctional adenoma is a tumor that does not produce any form of excessive hormones in an affected individual's blood. Because this type of pituitary tumor does not make its presence known until it has become large and began to press on other structures in the brain, it can be difficult to diagnose before it causes significant damage to the pituitary gland.
The first symptoms that typically present in patients who develop a nonfunctional adenoma include headaches, sexual function loss, fatigue, menstrual period loss, and weight loss. Nonfunctional adenomas are diagnosed with the use of MRI scans and blood tests. An endocrinologist can determine if and to what extent a patient's nonfunctional adenoma is affecting the hormone levels in the body. Out of all cases of pituitary adenomas, around fifteen percent are diagnosed as nonfunctional adenomas. For every 100,000 individuals, between seven and nine of them will be diagnosed with a nonfunctional pituitary adenoma.
Prolactin producing tumors, prolactinomas, are a type of very common but irregular growth that develops in the pituitary gland and causes it to produce an excessive quantity of a hormone called prolactin. Prolactin-producing tumors are not cancerous, but they can grow to a large size over time. Patients who have prolactinomas experience higher than normal levels of prolactin, which is most commonly known for its role in the stimulation of breastmilk but also plays a role in other processes in the body. Females who develop prolactinomas have symptoms related to low levels of estrogen. Low estrogen symptoms include irregular menstruation, infertility, skipped periods, and breast discharge.
Males who develop prolactinomas in their pituitary gland experience symptoms related to lower than normal levels of testosterone. Low testosterone levels cause erectile dysfunction, enlarged breasts, decreased body hair, and decreased facial hair. Prolactinomas produce low bone density, hypopituitarism, headaches, vision problems, and loss of interest in sexual activity in both sexes. Blood tests, vision tests, and brain imaging are used to make a diagnosis of prolactinoma.
Growth Hormone Tumors
A growth hormone-producing tumor is an abnormal growth in the pituitary gland that results in the production of high amounts of growth hormone. Growth hormone is a hormone that commands the liver to produce insulin-like growth factor 1, which plays a major role in numerous processes in the body, including metabolism, tissue growth, and bone growth. Most growth hormone tumors are noncancerous or benign, but in rare cases, they can progress into malignancy.
Individuals who have growth hormone tumors tend to present with some unique symptoms, the most serious being high blood pressure, arthritis, type 2 diabetes, and an increased risk of cardiovascular disease. Other symptoms of growth hormone tumors include voice deepening, an increase in spaces between the teeth as the jawbone grows larger, frequent kidney stones, abnormal foot growth, dramatic facial changes as the bones grow, increased sweating, headaches, abnormal skull growth, and abnormal hand growth.
Adrenocorticotropic Hormone Tumors
An adrenocorticotropic hormone tumor, also called an ACTH-producing tumor, refers to an abnormal growth in the pituitary gland that causes the production of too much adrenocorticotropic hormone. These tumors originate in corticotropic cells, which are responsible for producing ACTH. This hormone commands the adrenal glands to produce cortisol, which is also known as the stress hormone. Cortisol helps the body cope with all types of stress. This cortisol release and its subsequent effects work great for when the body is under stress from an injury, infection, or recent surgery.
However, numerous adverse effects arise when too much cortisol is in the body due to its production by an ACTH tumor, including unexplained weight gain, muscle weakness, high blood pressure, moodiness, insomnia, irregular periods, bone weakening, fractures, limb thinning, diabetes, easy bruising, and poor concentration. ACTH tumors are diagnosed through MRI scans of the patient's brain, urine tests, blood tests, and petrosal venous sampling.
Pituitary carcinoma describes when an individual develops an abnormal and malignant tumor in their pituitary gland. Pituitary cancer is an extremely rare occurrence and is typically not discovered until after death. The symptoms caused by pituitary carcinoma are similar to those that occur in benign pituitary tumors. Diagnosis of pituitary carcinomas is challenging because the differences between a malignant and benign pituitary tumor, even under a microscope, are difficult to distinguish. Patients diagnosed with pituitary carcinoma are usually only diagnosed once the malignancy has metastasized beyond the pituitary gland.
Pituitary carcinoma is known to spread into the brain and into regions outside of the brain, including the spinal cord, skull and other nearby bone, lymph nodes, blood vessels, meninges, eyes, lungs, liver, kidneys, heart, pancreas, and ovaries. Treatment for pituitary cancer includes excision surgery combined with radiation therapy to eliminate cancerous cells in the body, alongside any methods used for the treatment of its metastasis sites.