From the Guidelines
The workup of a goiter should begin with a thorough history and physical examination, followed by laboratory tests, including thyroid-stimulating hormone (TSH), free T4, and free T3, and thyroid antibodies (anti-TPO and anti-thyroglobulin), as well as an ultrasound of the thyroid to characterize the goiter and assess for nodules. According to the American College of Radiology (ACR) Appropriateness Criteria 1, imaging has a key role in diagnosing and characterizing thyroid findings for management.
Initial Evaluation
The initial evaluation of a goiter should focus on symptoms of hyper- or hypothyroidism, as well as any compressive symptoms like dysphagia or dyspnea. Laboratory tests, including TSH, free T4, and free T3, should be performed to assess thyroid function. Additionally, thyroid antibodies (anti-TPO and anti-thyroglobulin) should be measured to evaluate for autoimmune thyroid disease, particularly Hashimoto's thyroiditis.
Imaging
Ultrasound of the thyroid is essential to characterize the goiter's size, echogenicity, and presence of nodules. The ACR formed committees that published guidance regarding the incidental thyroid nodule detected on imaging, and ACR TI-RADS was conceived to aid management of thyroid nodules detected on ultrasound 1. If nodules larger than 1-1.5 cm are found, fine-needle aspiration biopsy should be performed to rule out malignancy.
Further Evaluation and Treatment
For large goiters with compressive symptoms, a CT or MRI scan may be necessary to assess extension into the thoracic cavity and compression of surrounding structures. Radioactive iodine uptake scan can be useful in cases of hyperthyroidism to distinguish between Graves' disease, toxic multinodular goiter, or toxic adenoma. Treatment depends on the underlying cause, ranging from observation for simple goiters to thyroid hormone replacement for hypothyroidism, antithyroid medications for hyperthyroidism, or surgery for large compressive goiters or suspicious nodules.
Key Considerations
It is crucial to note that goiters can represent various thyroid conditions, from benign physiological adaptations to malignant processes requiring prompt intervention. The workup is essential to determine the underlying cause and guide appropriate management. As stated in the ACR Appropriateness Criteria 1, goiter refers to abnormal growth and enlargement of the thyroid gland, and imaging plays a role in evaluation of non-neoplastic disease entities, such as goiter and thyrotoxicosis.
From the Research
Diagnostic Workup for Goiter
The diagnostic workup for goiter, which is the enlargement of the thyroid gland, typically involves several steps and tests. These include:
- Patient history and physical examination to assess for symptoms such as compressive symptoms or those related to hypothyroidism or hyperthyroidism 2
- Serum thyroid-stimulating hormone (TSH) determination to evaluate thyroid function 3, 2
- Free thyroxine (T4) and free triiodothyronine (T3) measurements to further assess thyroid function 3
- Imaging studies, such as:
- Ultrasound to evaluate the size and anatomy of the goiter, and to identify nodules that may require biopsy 4, 3, 2
- Scintigraphy to assess goiter function 4
- Sonographically guided fine-needle biopsy to evaluate nodules for malignancy 4
- Computerized tomography (CT) scans, especially for substernal goiters to assess the extent of mediastinal involvement 5
Treatment Options
Treatment options for goiter depend on the underlying cause, the size of the goiter, and the presence of symptoms. These may include:
- Observation for small, asymptomatic goiters 2
- Iodine supplementation for goiters caused by iodine deficiency 2
- Thyroxine suppression for non-toxic goiters to reduce the size of the gland 3, 2
- Thionamide medication (such as carbimazole or propylthiouracil) for hyperthyroidism associated with goiter 3, 2
- Radioactive iodine ablation for toxic multinodular goiter or solitary hyperfunctioning thyroid nodules 4, 3
- Surgery for large goiters causing compressive symptoms, suspected malignancy, or cosmetic concerns 3, 5, 2