The pituitary gland is often referred to as the master gland, as it produces hormones to control the functioning of various other endocrine glands. It is a small pea-sized gland and is located at the base of the brain. It is positioned in a bony chamber behind the back of your nose.
It lies below the hypothalamus and is attached to it by nerve fibers. The hypothalamus communicates with the pituitary gland by sending messages in the form of hormones. The pituitary gland receives these messages and adjusts its own production and release of hormones, and sends messages to other glands and organs in the body. The pituitary gland consists of three sections, the anterior lobe, the intermediate lobe, and the posterior lobe. As it has multiple tasks to carry out, each part produces a different hormone. The hormones produces by each of the lobes is given below.
- Growth hormone
- Prolactin, which stimulate milk production after childbirth
- ACTH (adrenocorticotropic hormone) which stimulates the adrenal glands
- TSH (thyroid-stimulating hormone) which stimulates the thyroid gland
- FSH (follicle-stimulating hormone) which stimulates the ovaries and testes
- LH (luteinizing hormone) which stimulates the ovaries or testes
- Melanocyte-stimulating hormone, which controls skin pigmentation
- ADH (Antidiuretic hormone), which increases absorption of water into the blood by the kidneys
- Oxytocin, which causes contractions in the uterus during childbirth and stimulate milk production
The most common problem the pituitary gland is likely to face, is the development of a tumor. These tumors are most often benign, i.e. non-cancerous. Quite often, the tumors do not cause symptoms and the condition is never diagnosed during a person's lifetime. However, sometimes they cause discomfort and may impede or increase the flow of hormones. The hormones perform critical functions and almost of any one can wreak havoc in our bodies. Pituitary tumors may be either non-functioning or functioning. Non-functioning tumors do not make hormones, while functioning tumors make excess of one or more hormone.
When a tumor produces extra hormones, any of the following symptoms may arise:
- Change in weight - weight gain or weight loss
- Enlarged hands, feet, skin changes
- Facial changes - enlarged jaw, tongue, bones of the face, moon face, puffy eyes
- Hair - coarse, thin head hair, loss of body hair, thinning eyebrows
- Headache, constipation, lethargy, or weakness
- Low blood pressure
- Nasal drainage
- Nausea and vomiting, seizures
- Personality changes - decreased sexual interest, irritability
- Problems with the sense of smell
- Temperature sensitivity- intolerance to cold or heat
- Visual changes - double vision, drooping eyelids
Symptoms that surface only in women are abnormal nipple discharge, stopping of menstruation, or excessive body hair. Symptoms seen exclusively in men may be breast development or impotence.
The condition that arises is in relation to the hormone that is being produced in excess. Central hypothyroidism is caused by excess supply of thyroid-stimulating hormone. Cushing syndrome is a result of excessive production of adrenocorticotropic hormone. Excess growth hormone manifests into gigantism or acromegaly, and prolactinoma is the result of an excess of prolactin.
Pituitary tumors may be sub divided into the following three groups:
- Benign pituitary adenomas: Tumors that are not cancerous fall into this category. These tumors grow very slowly and do not spread from the pituitary gland to other parts of the body.
- Invasive pituitary adenomas: These are benign or non-cancerous tumors that may spread to bones of the skull or to the sinus cavity below the pituitary gland.
- Pituitary carcinomas: These deadly tumors are malignant (cancerous). They spread to other areas of the central nervous system (brain and spinal cord) or outside the central nervous system. However, they occur very rarely.
Tests are carried out, depending on the symptoms being exhibited. They may include endocrine function tests to measure cortisol levels (Dexamethasone suppression test or Urine cortisol test), follicle-stimulating hormone (FSH) levels, insulin growth factor-1 (IGF-1) levels, luteinizing hormone (LH) levels, serum prolactin levels, testosterone/estradiol levels, thyroid hormone levels (Free T4 test or TSH test). Other tests include formal visual field testing and MRI of the head.
Treatment depends on the type and size of the tumor. A tumor may be removed through surgery or may be shrunken with the use of medication or radiation. Hormone replacement therapy may also be required in some cases.
If you experience any of the aforementioned symptoms (even one), it is best to consult your healthcare practitioner. Early diagnosis and treatment of a tumor is necessary, as it is the key to a good prognosis.