The pituitary gland, also known as hypophysis,is a small endocrine oval gland located inside of human head, at the base of the brain, which weights about 0.5 grams. Being a part of the endocrinesystem, it works in making and releasing hormones into the blood to regulate metabolism, growth and development, tissue function, sexual function, reproduction, sleep, mood, metabolism, hunger, and others. The pituitary gland produces hormones that run mostof the activity of other endocrine glands in the body by indicating them to produce and release different hormones.
Pituitary tumors normally originate in the cells of the pituitary gland. They can be non-cancerous (adenoma or benign) or cancerous; although they usually act benign tumors:
- Pituitary adenomas and craniopharyngiomas, which secrete too much of certain hormones.
- Chromophobe adenomas (adenomas of the chromophobe cells of the anterior pituitarygland), which are also pituitary adenomas (non-cancerous), but cause the pituitary gland tosecrete not enough of certain hormones.
In other cases, the tumor may degenerate. At the origin of the tumor, an abnormal cell, called “CrookeCell “which comes from the degeneration of normal cells of the pituitary gland, causing a type of pituitary cancer; it can be a local or advanced cancer. When a pituitary cancer spreads intonearby tissues or other parts of the body (metastasize), it is considered as a serious or metastasizedcancer.
Causes of Pituitary Tumors
The cells of the pituitary gland sometimes undergo changes that make their way of growth orbehavior abnormal. These changes can lead to the formation of non-cancerous tumors such aspituitary adenomas, or cancerous tumor (cancer). The good news is over 99% of pituitary tumors arenon-cancerous, although they can cause serious health problems in the patient. For instance, some tumors cause vision problems and head ache due to their location in the brain. Most pituitary tumors produce pituitary hormones, and generate different disorders as they release hormones.
In rare cases, changes in the pituitary cells can cause cancer. This is called pituitary carcinoma (or just pituitary cancer). Scientists do not know to this day, the reasons for the development of tumorfrom the pituitary gland, but these risks below are suspected:
Multiple Endocrine Neoplasia (MEN) – MEN consists of a group of inherited or genetic syndromes, that affect the endocrine system. There are several types of multiple endocrine neoplasia; each one has a different genetic mutation or an abnormal characteristic pattern in a gene. They can be cancer (carcinoma) or benign (adenoma).
Carney Complex – this hereditary conditionis a very rare genetic disorder that increases the risk ofdeveloping several types of tumors, such as pituitary tumors, adrenal tumors and other endocrinetumors. It can also increase the risk of the non-cancerous tumors called myxomas of the heart and skin, which is characterized by spotty skin pigmentation on lips, inner and outer corners of the eyes, the membrane lining (conjunctiva) of the eye, and around the genital area.
Familial Isolated Pituitary Adenoma(FIPA)– FIPA is an inherited disorder that increases the riskof suffering from non-cancerous pituitary tumors. IFAP is caused by a mutation of the AIP gene whichproduces a protein involved in the control of cell growth. AIP gene mutation leads to growth outsidecontrol of pituitary gland cells which then forms a tumor.
McCune-Albright Syndrome – this is a rare disorder that affects the bones, skin, and several hormone-producing (endocrine) tissues . People with McCune-Albright syndrome develop areas of abnormal scar-like (fibrous) tissue in their bones, a condition called polyostotic fibrous dysplasia.Individuals with this disorder are at increased risk of having pituitary tumor.