The term thyroid nodule refers to an abnormal growth of thyroid cells that forms a lump within the thyroid gland. Although the vast majority of thyroid nodules are benign (noncancerous), a small proportion of thyroid nodules do contain thyroid cancer. In order to diagnose and treat thyroid cancer at the earliest stage, most thyroid nodules need some type of evaluation.
Symptomatic benign thyroid nodules and inoperable thyroid cancers
Nodular thyroid disease is a very common finding in clinical practice, discovered by ultrasound (US) in about 50 % of the general population, with higher prevalence in women and in the elderly.
Most thyroid nodules do not cause symptoms. Often, thyroid nodules are discovered incidentally during a routine physical examination or on imaging tests like CT scans or neck ultrasound done for completely unrelated reasons. Occasionally, patients themselves find thyroid nodules by noticing a lump in their neck while looking in a mirror, buttoning their collar, or fastening a necklace. Abnormal thyroid function tests may occasionally be the reason a thyroid nodule is found. Thyroid nodules may produce excess amounts of thyroid hormone causing hyperthyroidism. However, most thyroid nodules, including those that cancerous, are actually non-functioning, meaning tests like TSH are normal. Rarely, patients with thyroid nodules may complain of pain in the neck, jaw, or ear. If a nodule is large enough to compress the windpipe or esophagus, it may cause difficulty with breathing, swallowing, or cause a “tickle in the throat”. Even less commonly, hoarseness can be caused if the nodule invades the nerve that controls the vocal cords but this is usually related to thyroid cancer.
The majority of thyroid nodules, benign by fine-needle aspiration, are asymptomatic, stable, or slow-growing over time and require no treatment.
Nevertheless, large thyroid nodules may become responsible for pressure symptoms, resulting in neck discomfort, cosmetic complaints, and decreased quality of life.
Thyroidectomy or lobectomy is very common and remains the first line treatment for malignancies.
Radiofrequency ablation (RFA) is a well-known, effective, and safe method for treating benign thyroid nodules and recurrent thyroid cancers. Indications include patients presenting with:
benign thyroid nodules with nodule-related symptoms (neck pain, dysphagia, foreign body sensation, discomfort, and cough);
benign thyroid nodules responsible for cosmetic complaints;
autonomously functioning thyroid nodules (AFTN); and
recurrent thyroid cancers, in the operation bed and lymph nodes, in patients at high surgical risk.
In this consensus statement, nodule size is not considered a specific criterion for RF treatment, although authors declare that “patients with nodules with a maximum diameter >2 cm that continue to grow, may be considered for thyroid RF ablation, based on symptoms and clinical concerns.” Indeed, large thyroid nodules may frequently cause local symptoms or cosmetic complaints and are therefore addressed through surgery or RF ablation more often than smaller ones. Nevertheless, small nodules may elicit symptoms or cosmetic discomfort too, depending on their location and on a patient’s feeling.