the thyroid nodules and thyroid cancer

personal notes of Dr.. Claudio Italian, internist

The thyroid nodules are common. In countries where iodine deficiency is detected, as in the U.S., the nodules are present in 4-7% of the general population. The frequency of sonographically detected nodule is 50% or more women aged over 60 years; Most nodules are benign but in series 5% are cancers. Since in Italy the presence of nodules is high, if not proceed to an examination of cases in which there is the indication for surgery, hundreds of thousands of patients may undergo surgery, but this does not happen because they are limited to interventions only to cases necessary and as we see below.

.. Nature of nodules.

The nodules are clinical expression of many thyroid diseases, may be single or multiple, in the context of an enlarged gland (multinodular goiter), where a nodule can appear only increased. The swellings simulating a nodule are also frequent and we talk about pseudo-nodules with thyroid hyperplasia, which is possible in Hashimoto's thyroiditis.

.

. Anatomo-pathological and clinical classification of thyroid nodules.


Pseudonodular
Hyperplastic and / or regressive


Inflammatory
Volunteer

Compensation after partial thyroidectomy



Acute bacterial thyroiditis
Subacute thyroiditis
Hashimoto's thyroiditis


Benign nodules
Cold nodules


Hot nodules
Solid or mixed cystic

Functioning adenoma


Malignant nodules


Primary tumors

Lymphoma

Thyroid metastasis from other cancers
Papillary carcinoma
follicular carcinoma
anaplastic carcinoma
medullary


.. Pseudo-nodules.



These nodules are not cancer, the expression of different diseases:

thyroid hyperplasia areas that may follow spontaneous partial thyroidectomy or involutional changes;
rare thyroid hemi-agenesis, occurring with a lobe hyperplasia.
Nodules formed by infiltrating lymphocytes in chronic autoimmune thyroiditis;
Nodules in subacute thyroiditis.
. True benign and malignant nodules.

And we come to the point. It 's the thyroid scan technique to distinguish the functioning nodules called "hot" than "cold" that do not light, so to speak, after injection of iodinated contrast material, because not pick up the dye and these nodules are why not just pick up cold and therefore do not work, that do not have the capacity to concentrate the tracer or have only a limited extent.



Features of the nodules.

The nodules are hot up to 20% of all thyroid nodules and their frequency is greater where there remains a lack of iodine are found in the genre more than 30 years, 3-4 times more in females, with very few exceptions are always benign .
Cold nodules are more frequent and represent 80% of all thyroid nodules. The thyroid ultrasound can distinguish three types of nodules: a) pure liquid, cystic, b) solid nodules c) nodules mixed. The nodules are solid and mixed in a proportion of 10%, malignant.


There seems to be, as we said, almost never malignant nodules in nodules between hot and cold cystic nodules. Over three quarters of nodules are malignant differentiated thyroid cancer, a departure from the follicular cells (papillary or follicular) in which the prognosis is generally favorable. Other types of cancer are represented by:

Anaplastic carcinomas, 5-15% of all thyroid cancers and have unfavorable prognosis quickly
Medullary thyroid carcinomas (MTC) arising from the parafollicular cells or C cells, which produces calcitonin.
Primary lymphoma of the thyroid.


Diagnosis.

It uses personal and family anamnesis, that is whether the family there were cases of medullary thyroid carcinoma must rise to the suspicion that the person we are looking at it is also affected. Moreover, the irradiation of the head in childhood predisposes to risk of thyroid cancer. Clinical examination palpation can already provide information about the size and characteristics of nodules of the thyroid gland and information about the presence or absence of lateral cervical adenopathy, adenopathy palpable, hard, irregular, fixed to neighboring tissues.

.
Clinical-anamnestic elements that direct the diagnosis of thyroid cancer.


Risk

Age <20 or> 60 years
+

Sex male> female
+

Irradiation on head
+ + +

Family members for medullary Ca
+ + +

Single nodules
+

Rapid growth of the nodule
+

Growth after suppressive therapy with LT4
+ +

Rigidity and hardness
+ +

Pain, dysphagia, dysphonia
+ +

Lymphadenopathy
+ +



The TSH and thyroid hormones can not differentiate benign and malignant nodules but reflects the functional state of the thyroid. A low TSH suggests that the nodule is autonomous, that produces hormone and "blocks" TSH. Hypothyroidism is common in Hashimoto's thyroiditis, Determination of thyroglobulin autoantibodies and anti tireoperossidasi identifies a form of autoimmune thyroiditis. The dosage of calcitonin circulating CT is an expression of medullary thyroid carcinoma. It 's just the cytological examination of the nodule, that is fine needle aspiration cytologic examination of material information in the sense that the diagnosis of cancer
 

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