Thyroid Nodules Ultrasound

Usually the next step after the initial examination is to undergo a thyroid nodules ultrasound. If the specialist has the equipment at the office, then the procedure can usually be done the same day. If not, you'll probably need to make an appointment with their referral. The following is an explanation of why doctors need to do an ultrasound.
  • The ultrasound is done to check the size of the gland.
  • The normal thyroid size is (4 to 4.8) x (1.0 to 1.8) x (0.8 to1.6) cm. Anything larger is considered an enlargement, or goiter.
  • The ultrasound is also done to look for any abnormal growths, called nodules.
  • The most important thing to know is that it is common to find nodules on the thyroid gland. These growths fall under three categories: hot, warm, and cold.
  • Ultrasounds cannot tell if a nodule is benign or cancerous.

Ultrasound Thyroid Nodules Findings:

  • The size of the nodule is not conclusive in differentiating a benign nodule from a malignant nodule.
  • Both benign and malignant nodules can grow.
  • Rapid growth in nodules is more indicative of malignancy.
  • Nodules that are mainly cystic (fluid-filled) have a higher rate of being benign. About 5% of cystic nodules have been malignant.
  • A complex nodule with vascularity has a risk of being malignant.
  • Avascular nodules are highly likely to be benign.
  • Elastography is used to distinguish the firmness of a nodule. Tissue from a malignant nodule is harder and firmer than that of a benign nodule.
  • Echotexture is inconclusive in differentiating malignant nodules from benign nodules
  • Nodules with a ‘spongiform’ appearance are almost always benign.
  • Taller than wide nodule shapes are more likely to be malignant.
  • Irregular shapes are found in both benign and malignant nodules. Thyroiditis, a benign condition, can cause an irregularly-shaped nodule.
  • Both benign and malignant nodules can have ill-defined margins.
  • Margins that are ‘spiculated’ are usually malignant.
  • While hypoechoic nodules can be found in benign nodules, ‘marked’ hypoechogenicity is more definite for a malignancy.
  • Microcalcifications have been found in both benign and malignant nodules.
  • Nodules with eggshell or rim calcifications along with hypoechoic halo and/or disruption of eggshell calcifications are suggestive of malignancy.
  • Solid nodules larger than 1 mm with macrocalcification is suspect for malignancy.
  • If an entirely even halo is found, it is frequently a benign nodule.
  • Over 50% of nodules lacking a halo are benign.
  • Hypervascularity has been seen in an average of 72% of thyroid nodule carcinomas.

Statistics on Thyroid Nodules:

  • It is widely known that 95% of all nodules are benign.
  • Hot nodules: 95% are benign.
  • Warm nodules: 90% are benign.
  • Cold nodules: 85% of all nodules are cold, and about 85% of the 85% are found to be benign.
  • Doctors will always further examine any cold nodule since the risk of malignancy is higher. They then order a biopsy to be done on the cold nodule.

Finding Worrisome Nodules:

Remember: ultrasound cannot tell the difference between malignant or benign nodules. If a doctor finds any of the characteristics of malignancy, especially when they are grouped, the next step is to perform a Fine-Needle Aspiration Biopsy (FNAB) to rule out cancer. Read on to find out more.

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