Lesions that are different from the surrounding thyroid parenchyma and can be separated radiologically are called thyroid nodules. While the frequency of palpable nodules is 3-7%, the frequency of nodules that cannot be detected clinically but detected in ultrasonography is reported between 20-76%. Most nodules are found incidentally during ultrasonography examination. The incidence of nodules increases with age.
When a nodule is detected in the thyroid in clinical practice, the most feared is that it may be malignant. However, it should be kept in mind that most of these lesions are benign. Thyroid nodules can be single or multiple, solid, cystic or mixed, functional or nonfunctional.
When a thyroid nodule is detected, the most important approach is to determine whether the nodule is benign or malignant. The probability of malignancy in nodules is 5%.
Factors Increasing the Risk of Malignancy in the Nodule:
- Seen in childhood
- Male gender
- New nodule over the age of 45
- Rapid growth of the nodule
- Being exposed to radiation or receiving radiotherapy to the neck in childhood
- Thyroid cancer in the family
- Cold nodule in scintigraphy (malignancy probability reaches 15% in cold nodules, malignancy rate is <1% in hot nodules.)
- The presence of a hard, fixed, irregular, large nodule on examination
- Risky ultrasonography view
- Ultrasonographic symptoms that increase the possibility of malignancy of nodules:
- Large nodule (> 4 cm)
- Not being halo
- Irregular edges
- Risky lymph nodes in the neck
- Hypoechogenic structure
- Increasing blood in mixed nodules
- In the transverse position, the height of the nodule being greater than its width
For which nodules should thyroid fine-needle aspiration biopsy be performed?
- All solid nodules larger than 10 mm
- Semisolid nodules larger than 15 mm
- Nodules with high malignant potential
Needle biopsy should be performed on people who have a family history of thyroid cancer, have had radiotherapy or radiation exposure in their childhood.
Biopsy is unnecessary if there is no risky appearance on the cyst wall in pure cystic nodules. If type B cysts are large, they can be drained.