The patient may seek medical attention because he/she has noticed a solitary lump in the neck. The cause for seeing a doctor may also be goitre that causes pressure symptoms or large cosmetic disturbance in the neck.
Sometimes a thyroid nodule or mild goitre is an incidental finding in an asymptomatic person when ultrasonography or other imaging examination of the neck is performed for some other reason. These patients are usually euthyroid, but TSH and free T4 concentrations should be determined to exclude a disturbance of the thyroid function.
A lump in the neck: nowadays ultrasonography of the neck distinguishes very reliably benign lumps from malignant ones. A fine-needle biopsy is taken, when needed, to assess the risk of cancer.
Goitre in a euthyroid patient needs no treatment if it does not cause cosmetic problems or compression symptoms or show signs of growth. If this should be the case, the patient is, if necessary, referred to specialized care to assess the need for surgery. If the size of the thyroid gland has increased substantially in a short time, ultrasonography is performed and, when needed, do not hesitate to have needle biopsy obtained.
In multinodular goitre, carcinoma as the cause ofany of the nodules is rare, but this possibility should be kept in mind.
A thyroid nodule
A solitary thyroid nodule may be
a benign cyst
a solitary goitre nodule
a part of multinodular goitre
caused by autoimmune thyroiditis (TPO antibodies positive, untreated hypothyroidism)
follicular adenoma
thyroid cancer (about 5 %).
Investigate serum free T4 and TSH in all patients with one or more thyroid nodules. Possible functional disturbance is corrected.
A carcinomatous nodule is usually hard and attached to the surrounding tissue. The symptom is usually fresh. In well differentiated carcinoma the nodule grows slowly, in undifferentiated carcinoma the growth is rapid.
The evaluation of multinodular goitre may be difficult by palpation only. Multinodular goitre has often been known for a longer time already.
Ultrasonography and fine-needle biopsy
Ultrasonography is the primary investigation after palpation. Benign lumps can be discerned well in that. The need for a fine-needle biopsy sample is assessed according to standardized criteria (ACR TI-RADS; the composition, echo pattern, shape, margin and calcification of the change are assessed in addition to the size http://www.acr.org/Clinical-Resources/Reporting-and-Data-Systems/TI-RADS).
A cyst causing pressure symptoms can be emptied by aspiration. Surgery may sometimes be necessary if the cyst causes symptoms continuously by refilling.
The so-called Bethesda classification is used in the classification and consultation responses of cytological samples.
If the cytology is suggestive of carcinoma, or if carcinoma cannot be excluded, the patient is referred for surgical treatment.
If the cytology reveals so-called follicular neoplasia, the patient is referred for surgical treatment. The final histopathological diagnosis is confirmed by lobectomy.
If the cytological finding is completely benign, the investigations are repeated once after 6 to 12 months. If the findings are still benign and the patient is symptomless, further investigations or follow-up are unnecessary.
Indications for surgical treatment
Cytological finding is malignant or suspicious.
The nodule is constantly growing, or it is large (≥ 4 cm), hard or causing compression symptoms.
The patient is young or worried.
The nodule recurs after repeated aspiration.
Follicular neoplasia as a cytological finding is problematic: the condition in question may either be a benign follicular adenoma or follicular carcinoma. The patient is referred for lobectomy.
If the finding is malign, total thyroidectomy is performed.
Rapid growth is an alarming sign also in goitre and warrants ultrasonography and consideration of sampling.
In multinodular goitre, carcinoma as a cause of a nodule is rare, but the probability of carcinoma in a dominant nodule is similar to the one in a solitary nodule. Surgical treatment is needed if the cytological finding unexpectedly is malignant.
Treatment is indicated if the goitre causes tracheal compression or cosmetic harm. The patient is then referred in order to assess the need for surgical treatment.
References
Cibas ES, Ali SZ. The 2017 Bethesda System for Reporting Thyroid Cytopathology. Thyroid 2017;27(11):1341-1346. [PubMed]
Tessler FN, Middleton WD, Grant EG, et al. ACR Thyroid Imaging, Reporting and Data System (TI-RADS): White Paper of the ACR TI-RADS Committee. J Am Coll Radiol 2017;14(5):587-595. [PubMed]