A pituitary tumor is an abnormal growth of cells within the pituitary gland. Most pituitary tumors are benign, which means they are non-cancerous, grow slowly and do not spread to other parts of the body, however they can make the pituitary gland produce too many hormones, which can cause problems in the body. Tumors that make hormones are called functioning tumors, and they can cause a wide array of symptoms depending upon the hormone affected. Tumors that don’t make hormones are called non-functioning tumors.
Their symptoms are directly related to their growth in size and include headaches, vision problems, nausea, and vomiting. Diseases related to hormone abnormalities include Cushing’s disease, in which fat builds up in the face, back and chest, and the arms and legs become very thin; and acromegaly, a condition in which the hands, feet, and face are larger than normal.
Most pituitary tumors are noncancerous (benign), nonspreading growths (adenomas). Adenomas remain confined to the pituitary gland or surrounding tissues and don’t spread to other parts of your body. The pituitary gland is a small bean-shaped gland located at the base of your brain, somewhat behind your nose and between your ears. Despite its size, the gland influences nearly every part of your body. Its hormones help regulate important functions, such as growth, blood pressure and reproduction.
The main types of pituitary tumors are adenomas (non-cancerous) and carcinomas (cancerous). Other types of pituitary tumors include microadenomas and macroadenomas. Pituitary tumors are categorized even further based on whether or not they produce hormones and what kinds of hormones are produced. Examples of these forms of pituitary tumors include prolactin-producing tumors (prolactinomas), ACTH-producing tumors, and nonfunctioning pituitary adenomas.
Symptoms of Pituitary Tumors
Tumors that secrete hormones tend to be smaller than the pituitary gland when they’re diagnosed. In fact, most pituitary tumors are microadenomas that measure 3 to 9 millimeters in diameter. Less common tumors are macroadenomas that are 10 millimeters or larger in diameter.
Pituitary tumors that produce hormones are called functioning tumors. Tumors that don’t produce hormones are known as nonfunctioning pituitary tumors.
A large tumor can grow upwards out of the sella turcica and compress the optic nerves (optic chiasm). Frequently, this leads to a specific form of “tunnel vision” called bitemporal hemianopsia.
Pituitary disorders resemble other endocrine disorders and have a broad range of symptoms. Symptoms depend on the type and location of the tumor and cause hormone excess, hormone deficiency, or pressure on the brain and central nervous system.
Rare tumors lead to secretion of excess thyroid, producing tremors, weight loss, diarrhea, and a sense of constantly feeling hot. Cushing’s syndrome occurs when there is excess adrenal secretion resulting in weight redistribution from the arms and legs to the trunk, thinning of the skin, rounding of the face (chipmunk facial appearance), fatigue, and hair thinning. When the back portion of the pituitary gland is affected the patient may notice excessive thirst and urination.
Pituitary tumor symptoms vary, depending on the size and location of the tumor. If the tumor grows large and presses on nearby parts of the brain, pituitary tumor symptoms, such as headaches or dizziness, can occur. A pituitary tumor can also press on the optic nerve, causing problems with vision.
In women, prolactinoma may cause irregular menstrual periods (oligomenorrhea), lack of menstrual periods (amenorrhea) and milky discharge from the breasts (galactorrhea).In men, a prolactin-producing tumor may cause male hypogonadism, which may involve signs and symptoms such as enlarged breasts (gynecomastia), erectile dysfunction (ED) or impotence, infertility, decrease in body hair, and loss of interest in sexual activity.