Pheochromocytoma, an Adrenal Medula Tumor

Endocrine SystemIn a clinical setting, patients often present with symptoms that could indicate a number of diseases or dysfunctions of their body’s systems. A dental patient may complain of intense tooth pain and believe that she needs a root canal; a thorough oral examination may reveal, however, periodontal infection that can be resolved with an antibiotic rinse. While a root canal surely would have eliminated any tooth pain, the patient would still have felt the gingival inflammation and felt the dentist was less-than-qualified when continued pain and further examinations revealed a different diagnosis altogether, one with a much simpler (and cheaper) solution. There are many symptoms that are related to endocrine gland dysfunction that can also be misdiagnosed, thus requiring not only thorough testing but also a process of elimination.

In this more in-depth example, we will consider the patient Mrs. James. She has made her appointment with the complaint of feeling an extreme sense of nervousness and constant sweating in addition to the feeling and even hearing of her heart beating loudly while she is trying to sleep in the evenings. Upon her arrival at the clinic, tests are performed that reveal three endocrine dysfunction symptoms: hyperglycemia, an increased basal metabolic rate, and high blood pressure. Additional tests indicate normal thyroid functioning. Using this information, a diagnosis can be made and treatment options can be presented to Mrs. James.

Using the process of elimination, we have already eliminated any thyroid gland problems. Anterior pituitary problems can also be eliminated for the following reasons: she has not noticed a thickening of the bones in her hands or face which would indicate growth hormone hypersecretion; a properly functioning thyroid eliminates thyroid-stimulating hormone imbalances; lack of the typical cushingoid signs – a “moon” face, a thickening of the trunk, and the appearance of fatty tissue on the posterior neck – eliminate adrenocorticotropic hormone imbalances; a lack of changes in her menstrual cycle indicate that follicle-stimulating hormone and luteinizing hormone are not to blame for her symptoms, nor are the steroid sex hormones released by her ovaries; and finally prolactin can be eliminated as the hormonal cause as Mrs. James symptoms are not related to lactation. The nearby posterior pituitary gland can also quickly be eliminated as the malfunctioning gland because oxytocin primarily affects the uterine smooth muscles and lactation and because antidiuretic hormone hyposecretion would cause diabetes insipidus and in turn hypoglycemia while ADH hypersecretion would cause headache, edema, and hypo-osmolarity of the blood – symptoms that she has not mentioned and that are not indicated by the blood tests. Parathyroid gland malfunction can be eliminated as blood tests did not show elevated blood calcium ion levels indicating hypersecretion of parathyroid hormone or the loss of sensation and muscle twitches that would indicate hyposecretion of PTH. The alpha and the beta cells of the pancreas deserve a longer look than the previously mentioned exocrine glands. While hypersecretion of insulin by the beta cells would cause hypoglycemia, hyposecretion by the beta cells or hypoactivity of the insulin hormone would cause the hyperglycemia seen in Mrs. James’ blood. However, as she is not presenting with any of the other classic signs of diabetes mellitus – polyuria, polydipsia, and polyphagia – they can be eliminated as the causal factor. Oppositely, hyposecretion of glucagon by the alpha cells of the pancreas would cause hypoglycemia while its hypersecretion would cause hyperglycemia; glucagon can be eliminated as the dysfunctional hormone as hypersecretion would also cause a fall in amino acid blood levels which was not noted in her tests. While Mrs. James is complaining of hearing and feeling her heart beat at night, the melatonin produced by the pineal gland is not to blame as she is not experiencing any problems with her other circadian-based activities such as body temperature or appetite. The final gland to be eliminated is her thymus as no immune system dysfunctions are seen. Cushing’s disease has already been eliminated, indicating that the adrenal cortex is not hypersecreting corticosteroids; the elimination of Addison’s disease with it accompanying weight loss and hypotension indicates that the adrenal cortex is also not hyposecreting the corticosteroids.

Adrenal MedulaIt is through this process of elimination that the adrenal medulla, with its catecholamine hormones of epinephrine and norepinephrine, is finally arrived at. As the catecholamines function with the sympathetic nervous system in the fight-or-flight response, an excess amount of them would cause Mrs. James to feel nervous and to sweat as her body felt itself preparing to respond to a stressor. In addition, this stress response would raise her blood sugar levels as her body ensures it has enough readily-available fuels to run far enough or hit hard enough. Hypersecretion of epinephrine appears to be the probable cause of her increased basal metabolic rate while hypersecretion of norepinephrine appears to be the probable cause of her hypertension. While more testing would be needed for a positive diagnosis, it may be that Mrs. James is suffering from pheochromocytoma, a tumor in the chromaffin cells of her adrenal medulla that causes hypersecretion of both epinephrine and norepinephrine.

After arriving at a diagnosis, Mrs. James must be presented with treatment options to eliminate the dysfunction or at least to ease her symptoms. An option that may initially present itself would be surgical removal of the adrenal medulla; due to its location within the important adrenal cortex, however, complete removal may be either impossible or have risks too great to be considered as a viable option. If further testing reveals a chromaffin cell tumor, then a treatment of focused radiation may be an option in an effort to kill the malfunctioning cells while attempting to leave the remaining healthy cells alive. If there is no tumor, Mrs. James could be encouraged to adjust her lifestyle to ease her symptoms. Lowering her caffeine intake may have a positive effect on both her basal metabolic rate and her blood pressure, as well as ease some of her nervous feelings. A modified diet and a solid exercise program may have a positive effect on both her blood glucose levels and her blood pressure. Finally, some meditative practices such as yoga or even simple meditation may also lessen Mrs. James’ nervousness and lower her blood pressure. While a clinician can encourage one treatment option over another and all of the options must ethically be presented with both their risks and rewards, the final decision must ultimately be left to the patient in hopes that it will be a well-educated decision rather than a knee-jerk reaction.

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