Acromegaly

Acromegaly is a tumor of the pituitary gland that causes increased thickening of the bones in the hands, feet, cheeks and jaw.  Acromegaly occurs in about 6 of every 100,000 adults and is usually caused by the production of excessive growth hormone after the skeleton is finished growing.  This overproduction of growth hormone is a result of a benign tumor of the pituitary gland.  Some common symptoms include but are not limited to; impaired vision, body odor, carpal tunnel syndrome, decreased muscle strength, easy fatigue, headache, excessive height, enlarged hands, feet, jaw and tongue, limited joint movement, thickening of the skin, and excessive hair growth in females.  This disease is most often diagnosed in middle-aged adults, but can appear at any age.  Patients with acromegaly are at high risk for developing type II diabetes, hypertension, sleep apnea syndrome, cardiovascular disease, arthritis, and colon polyps which could develop into cancer if left untreated.

Acromegaly is usually diagnosed utilizing several different tests.  Two of the usual tests are the growth hormone blood test and oral glucose tolerance test to determine if the patient has excessive growth hormone in the body.  Likewise the physician also uses imaging modalities after growth hormone tests to determine location and size of the tumor.  The physician will most likely order an MRI of the pituitary gland.  The MRI technologist will utilize sagittal and coronal T1 weighted spin echo images before and after the use of gadolinium.   In most cases a macroadenoma (tumor bigger than 10mm) will be found.  In a gadolinium enhanced MRI acromegaly is usually seen as a hypodense area where the pituitary gland is located.

There are usually three approaches to treatment for acromegaly; surgery, medical therapy, and radiation therapy.  Surgery is usually the first option and usually has the best outcomes.  During surgery the surgeon simply removes the tumor, which relieves the pressure and allows the hormone levels to lower.  It is important to note that even after surgery there is a chance of reoccurrence so patients may need medications and may need to continue to be monitored.  Medical therapy uses three classes of drugs (SSAs, GHRAs, Dopamine antagonists) for treatment in patients who are unable to have surgery or to shrink a tumor prior to surgery.  Radiation therapy is used for patients who still have some tumor left after surgery or whose bodies are unresponsive to medications, although it is important to note the effects of radiation therapy may not be seen for years.

                     The picture above shows a common symptom, enlargement of the hands.

       MRI image of a macroadenoma in acromegaly.  The image on the right shows the tumor

is only about 9mm in size. The tumor is far enough away that there is no impairment of vision.

MRI image of pituitary macroadenoma in an acromegalic patient.  The picture on the right shows the tumor with a diameter of 30mm.  The optic chiasm is elevated and compressed causing the patient loss of peripheral vision.