Pheochromocytoma

1
Pheochromocytoma

• Team Ramrod
• Elizabeth Bannister
• Matt Sweeny
• Kristina Kizer
• Andy Christensen
• Peter de Quiina

2
What is the problem?

• Phelix, a 22 year old male, is experiencing
  headache, palpitations, excessive sweating and
  weight loss.
• He is hyperglycemic, hypertensive, and he has
  normal thyroid hormone levels.
• His symptoms increase under stress.

3
So why did Dr. Dummy care about the thyroid gland?

• Phelix is exhibiting symptoms that are very
  common with hyperthyroidism, an excessive
  secretion of T3 and T4.
• Symptoms include increased metabolism, weight
  loss, palpitations, sweating, and arrhythmias.
• Dr. Dummy then tested his next hypothesis by
  giving Phelix Atropine
• A competetive inhibitor at PNS muscarinic
  receptors found in many tissues such as the
  heart, GI tract and blood vessels

4
What the is the deal with Phelix?

• Since thyroid hormone levels were normal and
  Phelix had an adverse reaction to Atropine, Dr.
  Dummy had reason to believe that there was a
  different endocrine problem.
• Pheochromocytoma a tumor in the adrenal medulla
  that results in the excessive secretion of
  epinephrine and norepinephrine

5
So what is this feokromoesightoma???

• The excess release of adrenal hormones puts
  Phelix in an uncontrollable state of fight or
  flight.
• Pheochromocytoma is also known as the 10 tumor
  because it kicks in only about 10 of the time.

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FIGHT or Flight

• Activation of the sympathetic nervous system
  releases epinephrine and norepinephrine which
  bind to the adrenergic alpha and beta receptors
  on target tissues.
• This triggers an increase in heart rate and
  breathing, constriction of blood vessels in many
  parts of the body and/or a tightening of muscles.

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Hyperglycemia

• Epinephrine binds to Alpha1 and Beta2 receptors
  in the liver which elevate the blood sugar level
  by increasing hydrolysis of glycogen to glucose
  (glycogenolysis).
• This explains why Phelix has an increased amount
  of glucose in his blood (hyperglycemia).

8
Weight LossYes!

• Epinephrine also binds to Alpha2 and Beta2 in
  adipose tissue and stimulates the release of
  fatty acids which causes the breakdown of fat.
• Phelix is also losing weight because the rest
  and digest functions of the enteric nervous
  system are being suppressed during the
  sympathetic nervous response.
• Alpha and Beta receptors of the GI smooth muscle
  respond to sympathetic situations by inhibiting
  gut motility.

9
Where is my Excedrin?

• The headaches Phelix are experiencing are a
  result of increased blood pressure (hypertension)
  and vasodilatation.
• Blood vessels in the brain dilate because of the
  fight or flight response and the slow pain
  pathway receptors in blood vessels transmit pain
  signals we can perceive.

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How do we know?

• Possible tests
• 24 hour urinary analysis for catecholamines
  (epinephrine, norepinephrine, and dopamine)
• Serum Blood Test for adrenaline by-products

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Fix me doc.

• Temporary treatment-Alpha blockers, such as
  Phenoxybenzamine and beta blockers such as,
  Propranolol and Atenolol, that block the
  receptors for catecholamines.
• Surgical treatment- minimally invasive
  laparoscopic adrenalectomy.
• Available in most hospitals in the US

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Analogy

• Devil sympathetic effects of pheochromocytoma
• Angel Parasympathetic nervous system