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Endocrine system




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A 44-year-old woman is brought to the emergency department an hour after developing acute confusion. According to her husband, the patient had been experiencing headaches and blurry vision for the past several hours. She has no significant past medical history. Temperature is 37.0°C (98.6°F), pulse is 102/min, and blood pressure is 205/110 mmHg. Physical examination shows right-sided weakness and loss of sensation. A CT scan of her head demonstrates an intraparenchymal hemorrhage. Despite appropriate treatment, the patient dies. A postmortem biopsy of her left adrenal gland is shown below:

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This patient most likely also experienced which of the following symptoms?

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pheochromocytoma and p. 345

Dopamine p. 243, 334

pheochromocytoma secretion p. 345

Epinephrine p. 243

pheochromocytoma secretion p. 345


pheochromocytoma p. 345

Norepinephrine (NE)

pheochromocytoma secretion p. 345


In pheochromocytoma, pheo- means dark, chromo- refers to color, cyto- refers to a cell and -oma means tumor. So a pheochromocytoma is a rare adrenal gland tumor where the cells darken when they form tumors.

Now, there are two adrenal glands, one above each kidney, and each one has an outer layer called the cortex and an inner layer called the medulla.

In the medulla, there are cells called chromaffin cells and their job is to make hormones called catecholamines. The catecholamines include epinephrine and norepinephrine - the fight or flight hormones.

Normally, the chromaffin cells in the adrenal gland secrete epinephrine and norepinephrine into the blood when something scary happens - like someone saying BOOM!

The epinephrine and norepinephrine bind to alpha and beta receptors in various tissues throughout our body and cause an increase in cardiac output, increased blood pressure, dilated pupils, increased blood flow to skeletal muscles, and increased blood sugar.

Pheochromocytomas are tumors that form when these chromaffin cells start to divide uncontrollably.

They typically form in one of the adrenal glands, but rarely can be in both and sometimes can even develop in other parts of the body where chromaffin cells are found like the carotid arteries in the neck, the bladder, and the abdominal aorta.


A pheochromocytoma is a neuroendocrine tumor of chromaffin cells in the adrenal medulla. Pheochromocytomas cause problems by producing too much of the catecholamines epinephrine and norepinephrine, which then causes sympathetic nervous system hyperactivity, resulting in symptoms like high blood pressure, headaches, palpitations, and sweating.

Pheochromocytomas are diagnosed by testing the urine for catecholamines and metanephrine; and imaging studies such as CT or MRI. Treatment involves surgical removal of the tumor, and medications to control blood pressure and heart rate.


  1. "Robbins Basic Pathology" Elsevier (2017)
  2. "Harrison's Principles of Internal Medicine, Twentieth Edition (Vol.1 & Vol.2)" McGraw-Hill Education / Medical (2018)
  3. "Pathophysiology of Disease: An Introduction to Clinical Medicine 8E" McGraw-Hill Education / Medical (2018)
  4. "CURRENT Medical Diagnosis and Treatment 2020" McGraw-Hill Education / Medical (2019)
  5. "Harrison's Endocrinology, 4E" McGraw-Hill Education / Medical (2016)
  6. "Failure to Recognize Multiple Endocrine Neoplasia 2B: More Common Than We Think?" Annals of Surgical Oncology (2007)
  7. "Multiple endocrine neoplasia type 2: An overview" Genetics in Medicine (2011)

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