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Pheochromocytoma: The Ten-Percent Tumor

Pheochromocytomas are often referred to as the "ten percent tumor" because they do many things about ten percent of the time. The following is a fairly exhaustive list of these characteristics:

10 percent of all Pheochromocytomas are:

  • Malignant (90% are benign)
  • Bilateral (found in both adrenal glands: 90% are arise in just one of the two adrenal glands)
  • Extra-Adrenal (found within nervous tissue outside of the adrenal glands ... see below)
  • In Children (90% are in adults)
  • Familial (10% will have a family member with the same type of tumor)
  • Recur (10% or slightly less, will come back 5 to 10 years later)
  • Associated with MEN syndromes (patients with rare syndromes of endocrine tumors.)
  • Present with a stroke (10% of these tumors are found after the patient has a stroke)

Here's a look at the extra-adrenal sites of pheochromocytomas:

  • Within the sympathetic nerve chain along the spinal cord (orange spots)
  • Overlying the distal aorta (the main artery from the heart) (green spots)
  • Within the ureter (collecting system from the kidney (yellow spot)
  • Within the urinary bladder (blue spot)
  • Remember, 90% are in the adrenal glands (red spots on the kidneys)