Thyroid cancer

Causes and Classification

Thyroid cancer is caused by the abnormal development of certain cells in this butterfly-like gland located at the base of the neck just below the Adam's apple.

Thyroid cancer very often manifests itself in a benign form and rather rarely in malignant forms (assuming in this case the name of thyroid cancer).

Benign tumors are particularly widespread, with an "incidence that is around 25-50% of the population: they are called benign nodules and in most cases do not cause particular problems, so much so that they go completely unnoticed or are occasionally discovered. during palpation or an ultrasound examination. Only in a minority of patients do thyroid nodules establish the typical symptom picture of thyrotoxicosis (excess of thyroid hormones) or grow to the point of creating problems with phonation and swallowing (by compression of the surrounding tissues).

Even more rare (less than 10% of cases) are malignant thyroid nodules, which can be of the following type:

papillary: the most widespread of all (70-80% of thyroid carcinomas), it is frequent in young patients (between 30 and 50 years old) and is characterized by a low degree of malignancy, which however tends to increase in older patients .
Follicular: represents 5 to 15% of all thyroid cancers and is found mostly among the elderly. It is more aggressive than papillary carcinoma, but maintains slow growth and a relatively favorable prognosis. Like the previous one, it affects the follicular cells of the thyroid (responsible for the synthesis of thyroid hormones T3 and T4).
Medullary: represents about 4-5% of thyroid tumors and develops at the level of C cells, responsible for the production of the hormone calcitonin. It generally affects people over the age of 50 and is characterized by some peculiarities: it can in fact be sporadic or family (hereditary transmission of abnormal genes) and associated with other tumors or pathologies of the endocrine system. Prognosis is good when the carcinoma is confined to the thyroid and poor in the presence of metastases.
Anaplastic: it is now a rarity among thyroid carcinomas (about 1% of cases), it is found in the elderly with long-standing voluminous goiter and has a "very high malignancy. It is characterized by" rapid and painful enlargement of the gland, affecting the follicular cells and is very difficult to treat.
Other rather rare forms of malignant tumors are represented by thyroid lymphoma and squamous cell carcinoma.

The incidence of thyroid cancer in the overall scenario of malignant neoplasms is around one, one and a half percent, ranging from 10 to 40 new cases per year per million inhabitants. The increased incidence documented in recent years seems to be due, at least in part, to the improvement in ultrasound diagnostic techniques.

More common among women, thyroid cancer causes - to a certain approximation - 6 deaths per year per million inhabitants.

Thyroid Cancer Symptoms

For further information: Thyroid Cancer Symptoms

As we have seen, thyroid cancer grows very slowly and is minimally invasive in most cases. There is therefore a long latency period between tumor induction and clinical manifestations; consequently the disease often remains undetected for life.

The characteristic symptom is the presence of a lump in the anterior region of the neck, corresponding to the anatomical site of the gland. As anticipated, however, only a small percentage of the nodules have malignant features.

Especially in young patients, the onset symptom may be represented by the enlargement of the laterocervical lymph nodes. In an advanced phase, this symptom can be associated with changes in the tone of the voice (hoarseness - dysphonia), pains spread in the anterior region of the neck and dysphagia (difficulty and pain in swallowing).

Risk factors

A nodule is more likely to turn out to be malignant when: it is not accompanied by thyrotoxicosis (it is classified as cold on the scintigraphic examination), it increases in consistency (classified as solid on the ultrasound examination), it has irregular edges and intraparenchymal vascularization (with echocolordoppler) and causes compression disorders (dysphonia, dysphagia). Other risk factors in this sense are represented by previous exposure to radiation (including those administered for therapeutic purposes or associated with nuclear disasters) and by the familiarity for goiter and for syndromes such as medullary thyroid cancer, multiple endocrine neoplasia and adenomatous polyposis familiar. The incidence of follicular cancer is also higher in iodocarent areas, where nodular goiter is endemic (which can be prevented through the use of iodized salt).