23rd May 2025

Nodular thyroid disease

Thyroid nodules are abnormal growths within the thyroid gland that are subdivided into benign ( ~ 95% of the cases) and malignant ones which are less common. Types of thyroid nodules are shown in Table 3.

Table 3: Types of nodular thyroid disease

Thyroid nodules are present in 50% of the population but only palpable in 5-10% of the population. They are more predominant in females and are more prevalent in inland regions where iodine content in food and water is low. Less than 5%  of these nodules can be malignant.

Clinical picture

The clinical picture depends on the activity and the virulence of the nodule. For example, the follicular type is considered an inactive nodule. whereas toxic adenoma and toxic multinodular goitre are considered active nodules, and  patients present with symptoms of hyperthyroidism. These nodules are usually painless. 

Thyroid cysts are due to cystic degeneration in the thyroid tissue or involution of adenoma. They usually present with a palpable nodule that can be tender due to haemorrhage inside the cyst or may cause  compressive symptoms such as hoarseness and dysphagia. Pemberton’s sign (facial erythema and jugular venous distension on raising the arms) is a sign of Superior Vena Cava (SVC) obstruction by a substernal mass. Thyroid nodules in pregnancy have shown increase in size and number with increase in malignancy risk. As a result, surgical removal can be indicated in the 2nd trimester or post-partum.

Malignancy should be suspected in patients <20 or >60 years old. Other red flags for malignancy can be male gender, history of radiation to the head and neck, rapidly growing nodules with compression symptoms, and firm fixed nodules that may be associated with cervical lymphadenopathy. Some genetic associations increasing risk of malignancy are:

• MEN2 syndrome
• Gardner syndrome
• Cowden syndrome
• Family history of thyroid malignancy.

Investigations

• Fine needle aspiration biopsy (FNAC). 
• Serum TSH: High levels are associated with higher risk of malignancy.
• Imagining can be thyroid US  or thyroid scintigraphy (which shows cold nodules are associated with malignancy, hot nodules are less likely to be malignant).
• Investigation of complications: e.g., symptoms suggestive of SVC obstruction from a goitre require CT imaging 

Management

NICE guidelines recommend management of nodular goitre depending on the activity of the nodules and virulence.

Management of non-toxic multinodular goitre may involve:

• Surgery
  • Compressive symptoms
  • Cosmetic reasons
  • Solitary nodule with FNAC suggestive of malignancy
• Radioiodine
  • Indications same as for surgery, in patients not fit enough to undergo surgery
• Medical treatment
  • Not generally used, but T4 replacement may be useful if TSH is detectable 

Management of toxic multi-nodular goitre: 

• Radioiodide management 
  • 1st line definitive treatment. 
  • That might be due to the accumulation of 131 I preferentially in the hot nodules , not the normal thyroid tissue causing an euthyroid state as a result
• Surgery 
  • Aims to remove the nodular tissue. 
  • For symptomatic relief 
  • Post-operative monitoring of the TFTs is advised as patients at risk of becoming hypothyroid and may require thyroxine replacement.
  • It is considered the 2nd line of management if ATDs fail if a patient is pregnant or fathering a child in 6 months.
• ATDs such as Carbimazole 
  • Effective for hyperthyroidism, but are not curative treatments 
  • There is a risk of recurrence when the medications are stopped.