Pheochromocytoma updated 11/2019
Oma from the Greek means tumor. Here we are dealing with a rare condition in which a tumor develops within the center of one of the two adrenal glands, each located on top of a kidney. Under normal circumstances, when the body is under stress, the adrenal glands produce two hormones, adrenaline also seen in the literature as epinephrine and noradrenaline or norepinephrine. They cause an increase in blood pressure , also called hypertension, as part of the bodies “ flight or fight” reaction to a stressful situation.
When a pheochromocytoma develops, it secretes large amounts of these two hormones either continuously or at varying times. A person’s blood pressure may rise to a point where it becomes life threatening, damaging other systems of the body, especially the heart and blood vessels.
But these hormones also can create the brittleness exhibited by a brittle type 1 diabetic. It does so by increasing sugar levels within the body ranging from mild to severe hyperglycemic levels. Let’s look at how these hormones function.
We know that within the liver the body stores excess glucose in the form of glycogen. Adrenaline stimulates the breakdown of glycogen to glucose increasing glucose levels.
It also aids in the conversion of fats to glucose.These hormones induce insulin resistance in muscle cells throughout the body. Since glucose can’t get into the cells to be broken down for energy, it accumulates in the tissues and blood stream. In the pancreas, these hormones inhibit insulin secretion and without insulin, hyperglycemic conditions prevail. At the same time they stimulate glucagon production which is used to raise glucose levels.
The combination of all these events leads to variations in sugar levels which would account for the brittle condition observed in a brittle diabetic if he or she were suffering from pheochromocytoma.
In the case of a stable type one diabetic with good glucose control, sudden worsening of glucose levels should arouse suspicions of a tumor developing within the adrenals.
If on the other hand a brittle diabetic exhibits the following symptoms of this disease, his or her physician should consider the possibility that tumor development within the adrenals may be occurring.
Symptoms : The symptoms exhibited by the patient is a direct reflection of epinephrine(adrenalin) and norepinephrine (noradrenalin) impact on tissues and organs within the body.
Weight Loss – These hormones increase metabolic activity and causes weight loss through increased energy expenditure while at the same time suppressing appetite.
Facial Pallor - They constrict vascular smooth muscles in cutaneous blood vessels of the face resulting in decreased blood flow and facial pallor.
Shaking or tremors - excessive levels of these hormones will cause noticeable tremor of the fingers and hand.
Abdominal pain and Constipation - They reduce smooth muscle activity in the gastrointestinal (GI ) tract reducing peristalsis (the wavelike contractions of smooth muscle that pushes contents of the canal forward ) reducing fecal output leading to constipation.
Profuse Sweating – they increase sweat gland activity
Blurred vision – intracranial pressure and cranial swelling caused by extreme hypertension impacts nerves associated with vision.
Hypertension (increase in blood pressure)- these hormones alter blood pressure by altering vascular resistance achieved through constriction and dilation of blood vessels.
Panic attacks- origin is unclear but increased adrenaline can cause it to occur.
Cardiac arrhythmias ( heart rhythm problems ) such as tachycardia (rapid heart rate over 100 beats/minute or atrial or ventricular fibrillation (irregular contraction of heart muscle)
Palpitations ( heart is pounding and/or racing) becoming more frequent and severe.
DIAGNOSIS -This condition mimics so many other medical conditions it is often overlooked on first contact. Adrenalin and noradrenalin belong to a class of compounds called catecholamines.
Diagnosis requires a combination of family history, exhibited symptoms plus lab tests for catecholamines and their breakdown products found in both blood and urine.
A CT (computed tomography)scan and MRI ( magnetic resonance imaging) are used to identify a mass lesion in or near the adrenal medulla.
TREATMENT – Since most masses are small and well defined minimally invasive surgical approach using laparoscopy is generally successful with a recorded 90% cure rate. Most of the metabolic abnormalities, including hyperglycemia, are corrected following surgical removal of the tumor. Close monitoring of blood glucose and insulin dosing is necessary following surgery since it is not uncommon for patients to develop hypoglycemia.
NOTE: 25% of the time these tumors occur at sites other than the center of the adrenal gland called the medulla and are referred to as extra-adrenal pheochromocytomas or paragangliomas. The incidence of a cancerous pheochromocytoma is estimated to be 3% to 36% depending on genetic background and primary tumor localization. Many older research papers list a cancer rate of 10%.