Armando Hasudungan
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Goitre and Nodules

Overview

Overview Goitre refers to an enlarged thyroid gland. Thyroid nodules are common in the general population, especially in women. Goitre results from follicular cell hyperplasia at one or multiple sites within the thyroid gland. Goitre can be classified based on morphology into diffuse or nodular.

  • Nodular thyroid denotes the presence of single or multiple palpable or nonpalpable nodules within the thyroid gland.

Prevalence rates range from 5 to 50%. Factors associated with increasing numbers and size of thyroid nodules include Graves disease and pregnancy. Low iodine intake is associated with an increased incidence of hyperfunctioning nodules (also called toxic adenomas). Thyroid nodules always raise the concern of cancer, although <5% are cancerous.

Definition
Goitre: Enlarged thyroid gland (Latin gutur meaning throat)
Thyroid Nodule: Cause of goitre. It is a discrete lesion distinct from the surrounding thyroid parenchyma. Most nodules are benign and only 5% to 12% of the nodules detected on ultrasonography are malignant. Most thyroid nodules, including thyroid cancers, are asymptomatic.

Classification

Thyroid Nodule based on Morphology
Diffuse Nodular
Pregnancy Multinodular goitre
Graves Disease Adenoma
Hashimoto’s Disease Carcinoma
Drug induced (lithium, amiodarone)
Iodine Deficiency

 

Thyroid Nodule based on Thyroid function status
Toxic Non-toxic (simple)
Graves Disease Pregnancy
Thyroiditis Drug induced (lithium, amiodarone)
Multinodular goitre Iodine Deficiency

Risk Factors

Risk Factors raising suspicion of thyroid malignancy
Age (<20 or >60)
Rapidly enlarging nodule
Localised symptoms including dysphagia, stridor or hoarseness
Previous exposure to radiation
Family History
Familial polyposis coli
Lymphadenopathy
Hashimoto disease

Signs and Symptoms

  • Asymptomatic
  • Often noticed by patients as a lump or protrusion in the lower anterior neck
  • Dysphagia or a choking sensation (Large nodules)
  • Cough (Large nodules)

Clinical Examination Nodules may be:

  • single or multiple
  • hard or soft
  • tender or nontender.
Remember Thyroid lump with normal TFT is thyroid malignancy until proven otherwise

Malignancy

  • Firm or hard non-tender nodule
  • fixation to adjacent tissue
  • Pemberton’s sign
Side note Pemberton’s sign is facial erythema and jugular venous distension upon raising the arms. It is a sign of superior venacaval obstruction caused by a substernal mass.

Differential Diagnosis

AETIOLOGY OF GOITRE
Diffuse Nodular
Pregnancy Multinodular goitre
Graves Disease Adenoma
Hashimoto’s Disease Carcinoma
Subacute thyroiditis (de Quervain’s)
Drug induced (lithium, amiodarone)
Endemic (iodine deficiency)

 

Differential Diagnosis of Neck Swelling
Congenital conditions Thyroglossal tract abnormalities
Brachial cyct
Tumours Thyroid
Salivary glands
Carotid body (Chemodectoma)
Sarcoma
Lipoma
Lymph nodes Primary Malignancy (Lymphoma, leukemia)
Secondary Malignancy (oesophagus, mouth, nasopharynx)
Inflammatory Conditions (tonsilitis, mononucleosis, HIV)
Diverticulae Oesophagus

Investigations

The primary goal when evaluating a thyroid nodule is to determine whether it is malignant.

First line Investigations

  • TSH levels
  • Thyroid ultrasonography

If ↓TSH

  • Radionuclide scintigraphy with technetium 99m or iodine 123
    • Hyperfunctioning nodules (toxic adenoma) OR
    • Entire thyroid gland is overactive (toxic multinodular goiter) OR
    • Hypofunctioning nodule (most likely cancer)

If TSH normal or ↑TSH

  • Fine Needle Aspiration Ultrasound Guided – one of four results:
    • Malignant
    • Suspicious
    • Benign nodule
    • Indeterminate or nondiagnostic
Remember Fine Needle Aspiration is for diagnosing malignancy

Aetiology

AETIOLOGY OF GOITRE
Diffuse Nodular
Physiological (Pregnancy) Multinodular giotre
Graves Disease Adenoma
Hashimoto’s Disease Carcinoma
Subacute thyroiditis (de Quervain’s)
Drug induced (lithium, amiodarone)
Endemic (iodine deficiency)
Remember Thyroid Carcinomas are mainly follicular or papillary (most common). Medullary cancers are rare.

Management

Non-toxic goitre 

  • Observation
  • Iodine supplement

Toxic Goitre (overactive thyroid or nodule)

  • Antithyroid drugs
  • Radioiodine
  • Surgery

Malignant/suspicious thyroid or nodule

  • Surgery – partial or total thyroidectomy +/- lymph node involvement
    • Check thyroidglobulin levels (should be low) following thyroidectomy
    • Consider suppressing TSH
Indication for thyroid surgery
Troubling compressive symptoms
Fail to respond to medical therapy
Suspicious thyroid nodule
Malignant thyroid nodule
Cosmetic

 

Complications

Complications of thyroidectomy

  • Recurrent laryngeal nerve damage
  • Hypoparathyroidism
  • Thyroid crisis
  • Local hemorrhage, causing laryngeal edema
  • Wound infection
  • Hypothyroidism
  • Keloid formation

References

Knox, MA,. 2013, Thyroid Nodules, American Family Physician, vol. 88, no. 3, pp.193-196.
Hughes, K., Eastman, C., 2012, Goitre: Causes, investigation and management, Australian Family Physician, vol. 41, no. 8, pp. 572-576.