Question

Thyroid

Why can benign tumors still be dangerous?

A Answers (2)

  • AMichael Roizen, MD, Internal Medicine, answered
    Some tumors don't have cancer cells; this means that they're benign. However, the dictionary definition of 'benign' doesn't apply perfectly here, because a benign tumor can still be dangerous. Why? Benign tumors can grow to block off the pathway of important nutrients and bloody supply throughout the body. That's why surgery is sometimes necessary to remove benign tumors-to re-open the roads for nutrients to get to the organs.
  • AJack Merendino, MD, Endocrinology Diabetes & Metabolism, answered
    We should start by emphasizing that most benign tumors are not dangerous. Having said that, a tumor can cause problems by where it is located or by how large it is. For example, a benign pituitary tumor may cause problems because it is large and is pressing on the optic nerve in the brain, causing vision loss. Or a large thyroid tumor may be compressing the trachea, causing breathing problems. I’ve mentioned endocrine tumors because that’s my specialty, but these same considerations may apply to non-endocrine tumors. One thing that is specific to endocrine tumors, however, is over-production of hormones. Many benign tumors cause problems because they are producing hormones in amounts that are too large or in ways that are not properly regulated. A common example of this would be a pituitary tumor that is making too much prolactin. These tumors are almost never cancerous and they are usually not that large, but they often cause problems because the excess prolactin leads to breast enlargement in men or breast milk production in both men and women, and too much prolactin often causes irregular periods and infertility in women or a low testosterone level in men.  
Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.
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