Written by Sanjay Athavale, MD | Top Cumming ENT Doctor
What are Thyroid Nodules?
Thyroid nodules are abnormal growths of thyroid cells, which form a lump on the thyroid gland. However, nodules of the thyroid are much more likely to be benign than malignant. The approach to the evaluation of these nodules is, however, dictated by the need to identify those tumors which are malignant.
Clinically, thyroid enlargement may be smooth and diffuse or nodular, with the nodules being either single or multinodular. A smooth, diffuse enlargement typically is a sign of benign thyroid disease. However, even though it’s rare, anaplastic carcinoma or lymphoma may present this way. Consider these cancers if there are features of infiltration or metastasis.
Malignant or Benign?
A true single nodule is far more likely to be an abnormal mass and carries a 5-10% chance of malignancy. Fortunately, 90% of these are well-differentiated carcinomas, and with proper treatment, these patients have a very good prognosis.
An enlarged thyroid gland may cause pressure on adjacent structures, such as the esophagus and trachea. As a result, patients may complain of dysphagia (difficulty swallowing) or present with stridor (noisy breathing). Retrosternal extension occurs when the thyroid enlarges down into the chest, which may cause facial edema and venous engorgement of the neck.
A mass that rapidly increases in size, particularly if associated with pain, is typically a sign of malignancy. Infiltration of the strap muscles (a group of four pairs of muscles in the front of the neck) and skin may cause tethering, which is apparent when the patient swallows. If the larynx or trachea is invaded, it will cause stridor or hemoptysis. If it involves the recurrent laryngeal nerve, hoarseness will occur. Other structures involved may include the cervical sympathetic chain, cranial nerves, brachial plexus, and great vessels.
A fine-needle-aspiration biopsy is a type of procedure which can help distinguish benign from malignant tumors. The diagnostic accuracy is excellent for papillary, anaplastic, medullary, and overtly malignant follicular cancers. An FNA should be performed on all nodules >1 cm. If there is a history of radiation therapy to the head and neck, a family history of thyroid cancer, or the ultrasound is suspicious (nodules with microcalcifications, solid architecture, or a vascular periphery), it should be performed on those <1 cm as well. Ultrasound-guided FNA, as opposed to FNA by palpation (examination using hands) alone, should be used if the nodule is deep and >50% cystic. Depending on the FNA results, surgical management falls into two groups: those with confirmed malignancy preoperatively and those with indeterminate results.
In general, patients with well-differentiated cancer do extremely well with excellent long-term survival. In low-risk patients, the mortality rate is 1 to 2%. High-risk patients (older age, males, large tumors, extrathyroidal extension) and those with unfavorable histology, medullary, or anaplastic carcinoma tend to not do as well.
If you are experiencing any issues with your thyroid, call NAENTA at (770) 292-3045, or fill out a request form.