General information about thyroid nodules

The incidence of nodules in the whole population is 3-7% by examination, 50-60% by autopsy series and 50-70% by high resolution ultrasonography.  Thyroid nodules were found to a large extend in the thyroid glands of people who died for other reasons.  Most of these nodules do not have clinical relevance and some do not even need to be examined. The nodules are examined by deciding which test should be performed with which nodule.

Most of the nodules are not palpated by examination.  The large part of them is small nodules, which are incidentally detected during ultrasonography. There is no difference between large nodule and small nodule in terms of risk of cancer.  Therefore, any identified nodule should be evaluated from the point of cancer risk. A thorough evaluation performed in this way prevents unnecessary thyroid surgeries.

The incidence of thyroid nodules is four times more common in women than in men and this incidence increases with increasing age.  The cancer rate of thyroid nodules is between 5-15% depending on the risk factors. The risk of cancer is higher in men.  There is no significant difference between single nodule and multiple nodule from the point of probability of developing cancer.  The identified nodules are mostly multiple nodules and they are localized in both lobes of the thyroid gland.

When thyroid nodule is identified, thyroid function is determined by analysing thyroid hormones.  The next step is to evaluate the nodules by ultrasonography and to perform needle biopsy for suspicious nodule, if any.  Thyroid scintigraphy is not requested in each patient with the identified nodule. Thyroid scintigraphy should be requested for the differential diagnosis of hyperthyroidism in patients with low TSH levels.

The appearance of a "cold nodule" in a thyroid scintigraphy should not cause a cancer panic in patients, because 80% of benign nodules are visualized as cold nodules. 

           

Nowadays, the use of imaging methods such as ultrasonography, tomography and MR has increased the incidence of nodules.  The presence of an uptake on a thyroid nodule in PET imaging that is performed for other reasons indicates that this nodule has 30% of the risk of cancer and then biopsy is required. Ultrasonography and needle biopsy are the gold standard tests for the examination of the thyroid nodules.


Risk factors of developing thyroid nodule

  • Advanced age
  • Female gender
  • Iodine deficiency
  • Exposure to Low-Dose Radiation in the had and neck region
  • TSH receptor gene mutations

Findings that suggest malignant nodule (cancer)

  • Advanced age and especially male gender
  • Childhood and adolescence
  • Rapid growth of the nodule size (hemorrhage is considered if accompanied by pain)
  • Recently arisen nodule
  • Family history of medullary cancer
  • Family history of papillary thyroid cancer
  • History of radiotherapy on the head and neck
  • Hard, immobile nodule
  • Subsequent hoarseness
  • In addition to the thyroid nodule, swelling and growth of lymph nodes

Findings that suggest benign nodule

  • History of Hashimoto or autoimmune thyroid disease in the family
  • Family history of goitre
  • Findings of hypothyroidism or hyperthyroidism
  • Painful nodule
  • Soft, mobile nodule
  • Positive thyroid antibodies (autoimmune thyroid disease)

When is surgery necessary for thyroid nodules

  • Cancer or cancer suspicion in the needle biopsy result
  • Goitre composed of large nodules and the compression of this goitre, creating aesthetic defect
  • Hyperthyroidism (toxic goiter) caused by releasing more hormones from the nodules
  • In nodular goiter patients, bilateral thyroid gland is removed during surgery that means total thyroidectomy is performed.  Each patient is detailedly examined and the decision for surgery is made.