Pathophysiology of a Pituitary Tumor

The University of Maryland Medical Center (UMMC) says a pituitary tumor is an abnormal growth in the pituitary gland which is located at the base of the brain. This is the part of the brain that controls the balance of hormones. The majority of pituitary tumors are benign (noncancerous) and do not spread to other areas of the body. Various treatments are available for pituitary tumors and the possible fluctuation in hormone levels that may result from these irregular growths.

Causes

• The pituitary gland is a small pea-shaped gland. The exact cause of uncontrolled cell growth that ultimately creates a tumor in the pituitary gland remains unclear.

  The Mayo Clinic says scientists believe genetics may play a significant role in the development of these abnormal growths.

Effects

• According to the UMMC the pituitary controls the discharge of hormones that help control vital functions, such as growth, reproduction and blood pressure.

  Approximately 75 percent of pituitary tumors release hormones which include adrenocorticotropic hormone (ACTH), growth hormone (GH), prolactin and thyroid-stimulating hormone (TSH).

Hormonal Problems

• A variety of conditions can result when one or more of these hormones become imbalanced. Possible disorders include Cushing syndrome (occurs when your body produces too much cortisol), central hypothyroidism (thyroid gland fails to produce enough thyroid hormone) and acromegaly (a metabolic condition from too much growth hormone).

Symptoms

• The symptoms associated with a pituitary tumor are both attributable to the growth itself as well as the hormonal issues that it causes.

  Symptoms connected to pressure from the tumor include headaches, nausea, vomiting, fatigue, weakness and possible seizures. There may also be vision problems.

  Symptoms linked to changes in hormone levels will vary depending on the specific hormone but they may include weight gain, high blood pressure, irregular heartbeat and erratic menstrual cycles in women.

Diagnosis

• When diagnosing a pituitary tumor your doctor may test your blood and urine which can detect an oversupply or under-supply or hormones. Vision tests may be performed to see if a pituitary tumor is hampering your eyesight.

  A computerized tomography (CT) or magnetic resonance imaging (MRI) scan of your brain can assist your doctor in the locating and detecting the size of a pituitary tumor.

Treatment

• The National Institute of Health (NHI) says although pituitary tumors are usually not cancerous, they can pose serious problems when they apply pressure on nerves and blood vessels.

  Surgery may be necessary especially if the tumor is compressing the optic nerves, which could result in blindness. In most cases pituitary tumors can be removed through the nose and sinuses.

  Radiation therapy and some medications may help shrink the tumor. Medications include bromocriptine, cabergoline and pegvisomant.