Overview of pituitary adenoma
The pituitary gland is a small pea-sized organ in the brain. Most pituitary tumors are benign.
The pituitary gland produces hormones that control and regulate many other glands in the body. These glands release hormones that help control and regulate growth and the way the body works. The pituitary gland is divided into two parts forward and back:
The anterior pituitary produces a number of different hormones
- Growth hormone : controls growth
- Prolactin: stimulates breast milk production after childbirth
- ACTH: stimulates hormone production from the adrenal glands
- TSH: stimulates hormone production from the thyroid gland to help control growth, metabolism and reproduction
- FSH: ovarian stimulating hormone in women
- LH: hormone that stimulates the testes in men.
- ADH: hormone that reduces the amount of urine produced by the kidneys
- Oxytocin: stimulates uterine contraction during childbirth and releases breast milk for breastfeeding.
What is a pituitary tumor?
Pituitary tumors begin in the pituitary gland where production and help regulate hormones. Pituitary tumors are sometimes called benign adenomas. But they can cause the pituitary gland to produce too little or too many hormones that cause problems in the body.
- Pituitary tumors produce too many hormones that cause other glands to make more hormones, which will cause symptoms associated with specific hormones.
- Many pituitary tumors will also squeeze into nearby optic nerves that can cause vision problems.
Most pituitary tumors cause no symptoms and are not diagnosed. They are only found in a normal brain imaging test. About 25% of people may have small pituitary tumors without knowing it.
Types of pituitary adenoma
Main pituitary tumors:
Adenomas are not functional
- Tumors are the most common type and they do not make extra hormones. You may not have any symptoms until the tumor is of a certain size. When the tumor is large enough it can cause headaches and vision problems.
- Large pituitary tumors can crush normal pituitary cells. This leads to symptoms caused by a decrease in hormone production.
The tumor produces prolactin
- Benign tumors are also common, producing too much prolactin. If you are a woman, high prolactin levels can make your menstrual cycle irregular or even stop your period. These tumors can also cause you to make breast milk even if you are not pregnant or breastfeeding.
- If you are a man, you may have erectile dysfunction or lack of interest in sex. You may also have large breasts, low sperm count or little body hair. In the long run you may have headaches and vision problems.
The tumor produces ACTH
- ACTH stimulates the adrenal glands to create steroids that affect a metabolism called glucocorticoids. It reduces redness and swelling all over the body, it also slows down your immune system.
- Too much ACTH can cause Cushing’s disease, which causes fat accumulation on your face, neck, back, abdomen and chest. Also your arms and legs tend to become thin, you may also have purple stretch marks and high blood pressure. These tumors can also weaken your bones.
The tumor produces growth hormones
These tumors create too much growth hormone. In children, too much growth hormone stimulates the growth of most bones in the body. When that happens the result is called gigantism.
Gigantism can include height growth very fast, joint pain and excessive sweating. In adults, too much growth hormone causes a condition called acromegaly. It may include:
- Extra growth in the skull, arms and legs
- Bass voice
- A change in face appearance because of the further development in the facial bone
- A wide gap of teeth because of the development of the facial bone
- Snoring or sleep apnea
- Diabetes or impaired glucose tolerance
Causes pituitary adenoma
The cause of uncontrolled cell growth in the pituitary gland, creating a tumor, is still unknown. However, there are some risk factors related to family genetic genes such as:
- People with a family history of certain inherited diseases such as endocrine type 1 (MEN 1) are at risk for pituitary tumor.
- In MEN I many tumors occur in different glands of the endocrine system. Genetic testing is available for this disorder.
Symptoms of pituitary adenoma
Symptoms depend on the type of tumor and the affected area of the pituitary gland. These tumors can lead to symptoms caused by too much or too little pituitary hormone.
Pituitary tumor does not work
Sometimes a pituitary tumor can press on or damage parts of the pituitary gland, causing it to stop producing one or more hormones. Too little of a certain hormone affects the work of the gland or organ that hormones control.
The following signs and symptoms may occur:
- Some lose sight.
- Loss of body hair.
- In women with little or no menstruation or no milk ducts.
- In men: facial hair loss, breast tissue growth and impotence.
- In women and men: decreased libido.
- In children: growth retardation and sexual development.
Most tumors that produce LH and FSH do not make enough hormones to cause signs and symptoms. These tumors are considered to be inactive.
Pituitary tumor works
When an active pituitary tumor makes more hormones, the signs and symptoms will depend on the type of hormone produced.
Too much prolactin can cause:
- Some lose sight.
- Little or no menstrual cycle
- Trouble during pregnancy or inability to get pregnant.
- Helpless in men.
- Lower libido.
- There is milk in a non-pregnant woman.
Too many ACTH
- Some lose sight
- Weight gain on the face, neck and torso of the body, and thin arms and legs
- A lump of fat behind the neck
- Thin skin may have purple or pink stretch marks on the chest or abdomen
- Easy bruising
- The growth of fine hair on the face, upper back or arms
- Brittle bones
- Anxiety, irritability and depression
Too much growth hormone
- Some lose sight
- In adults: acromegaly (the development of bones in the face, arms and legs)
- In children: the whole body may grow taller and bigger than normal
- Pain or numbness in hands and fingers
- Snoring or stopping breathing during sleep
- The painful part
- Sweating more than usual
Too much thyroid stimulating hormone
- Irregular heartbeat
- Weight loss
- Difficulty sleeping
- Frequent bowel movements
Other common signs and symptoms of pituitary tumor
- Nausea and vomiting
- Runny nose much
Each person’s symptoms may vary. The symptoms may also look like other health problems.
Many pituitary tumors do not require treatment. Treatment depends on the type of tumor, its size and how far it has grown in your brain. Your age and overall health are also factors.
Treatment may include:
- Tumor removal surgery : Surgery is usually a better option for smaller tumors.
- External radiation: This treatment sends high levels of radiation to cancer cells. Special shields can be used to protect tissues around the treatment area. These treatments are painless and usually last a few minutes.
- Radiological surgery or gamma scalpel surgery: This uses a high dose of radiation delivered right into the cancer tissue. It causes little damage to nearby tissues. It is not surgery but like surgery to help remove a tumor.
- Pharmaceuticals: Different drugs can be used to control the amount of growth hormone generated by tumors.
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