If someone has thyroid cancer wouldn't the CBC blood test show that something was abnormal?

Question

I know it can't tell you what type of cancer but wouldn't the red and white blood cell count come back as abnormal?

Answer 1

No.  I had a large lymph node that none of my doctors did anything about because my thyroid levels and my CBC levels were perfect.  It turned out I'd had thyroid cancer for at least 2 years.  I kept telling them something was wrong with me - I kept getting infections, etc.  Then I got this lump and we found the cancer.  It turned out I had it in my thyroid, 7 lymph nodes in my neck, and 4 lymph nodes in my chest near my heart.  I have it again in both neck and chest now and my CBC levels are still just fine.  I think your white blood cells only go up with certain cancers (like leukemia) or in certain people.

Answer 2

No. The CBC only looks at very basic blood cells in your body. These cells can be completely normal in a person with cancer, although they almost always vary when a person is undergoing treatment or has very advanced disease. What you need is to look at the thyroid levels which will show if they are increased, which is common in thyroid tumor. Your symptoms and the physical exam will often point more directly to the cause. A biopsy is needed to confirm a cancer diagnosis.