Goitre

Goitre refers to the abnormal enlargement of the thyroid gland, which can be due to various causes. Its management largely depends on the underlying cause, size of the goitre, and associated symptoms.

Causes of Goitre:

  • Iodine Deficiency: Most common worldwide cause.
  • Hashimoto’s Thyroiditis: An autoimmune disorder leading to hypothyroidism.
  • Graves’ Disease: Autoimmune disorder causing hyperthyroidism.
  • Multinodular Goitre: Enlargement due to multiple thyroid nodules.
  • Thyroid Nodules: Can be benign or malignant.
  • Thyroid Cancer
  • Pregnancy: Due to hormonal changes.
  • Certain Medications: Like lithium, amiodarone.

Diagnosis:

  • History:
    • Symptoms: Presence of neck swelling, difficulty swallowing or breathing, hoarseness, thyroid-related symptoms (hyperthyroidism or hypothyroidism).
    • Duration: How long the swelling has been present.
    • Family History: Of thyroid disease or goitre.
    • Medication and Dietary History: Iodine intake, use of thyroid-affecting drugs like lithium and amiodarone
  • Physical Examination:
    • Thyroid Gland: Size, symmetry, nodularity, tenderness.
    • Neck Examination: For lymphadenopathy.
    • Thyroid Function Signs: Assess for signs of hypo- or hyperthyroidism.
  • Investigations:
    • Thyroid Blood Tests (see below)
    • Ultrasound of the Thyroid: To evaluate structure and identify nodules.
    • Fine-Needle Aspiration Biopsy: For suspicious nodules.
    • Radioiodine Uptake Test: To assess thyroid functioning.
    • Blood Tests: For antibodies (in autoimmune thyroiditis).
    • Imaging Studies: CT or MRI if goitre is large or retrosternal.

Differential Diagnosis (DDx):

  • Thyroid Nodules
  • Thyroiditis
  • Thyroid Cancer
  • Lymphadenopathy
  • Parathyroid Tumors

Management:

The management depends on the underlying cause, size of the goitre, and presence of symptoms.

  • Iodine Deficiency Goitre:
    • Iodine Supplementation
  • Hashimoto’s Thyroiditis:
    • Levothyroxine if hypothyroidism is present.
  • Graves’ Disease:
    • Antithyroid Drugs: Carbimazole, Propylthiouracil.
    • Radioactive Iodine Ablation
    • Surgery: In refractory cases or large goitres causing compression.
  • Multinodular Goitre and Thyroid Nodules:
    • Observation: If benign and asymptomatic.
    • Thyroid Hormone Suppression Therapy: In certain cases.
    • Surgery: For large, symptomatic goitres or if malignancy is suspected.
  • Thyroid Cancer:
    • Surgical Removal
    • Radioactive Iodine Therapy
    • Thyroid Hormone Therapy
  • Supportive Care:
    • Monitoring: Regular follow-up with ultrasound and thyroid function tests.
    • Compression Symptoms: Addressing difficulty in breathing or swallowing, if present.
  • Referral:
    • Endocrinologist: For complex cases or uncertain diagnosis.
    • Surgeon: For consideration of surgery in large goitres or cancer.
  • Follow-Up and Monitoring:
    • Regular follow-up to monitor the size of the goitre, thyroid function, and response to treatment.
    • Lifelong monitoring may be required in chronic conditions like Hashimoto’s thyroiditis or after treatment for Graves’ disease.
  • Patient Education:
    • Importance of regular follow-up.
    • Understanding the signs and symptoms of thyroid dysfunction.
    • Dietary advice regarding iodine.

Management should be individualized based on the cause, clinical presentation, and patient’s overall health.

Thyroid Blood Tests

Thyroid blood tests are essential tools for assessing thyroid function and diagnosing thyroid disorders. The primary tests include:

  1. Thyroid-Stimulating Hormone (TSH): Measures the level of TSH, a pituitary hormone that stimulates the thyroid gland. It is the primary screening test for thyroid dysfunction.
  2. Free Thyroxine (Free T4): Measures the free, or unbound, T4 hormone in the blood. T4 is one of the hormones produced by the thyroid gland.
  3. Free Triiodothyronine (Free T3): Measures the free T3 hormone in the blood. T3 is another hormone produced by the thyroid gland, though in smaller amounts than T4. It is more potent than T4.
  4. Total Thyroxine (Total T4): Measures the total amount of T4 in the blood, including both bound and free T4.
  5. Total Triiodothyronine (Total T3): Measures the total amount of T3 in the blood, including both bound and free T3.
  6. Thyroid Peroxidase Antibodies (TPO Antibodies): These are tested to diagnose autoimmune thyroid conditions like Hashimoto’s thyroiditis.
  7. Thyroglobulin Antibodies (TG Antibodies): Also used to detect autoimmune thyroid disease (TPO preferred)
  8. Thyroid-Stimulating Hormone Receptor Antibodies (TSHR-Ab): Includes stimulating (TSI) and blocking antibodies, mainly tested for in Graves’ disease.
  9. Thyroglobulin (TG): Measured to monitor treatment in thyroid cancer patients.
  10. Calcitonin: Primarily used in the diagnosis and monitoring of medullary thyroid cancer.
  11. Reverse T3 (rT3): An inactive form of T3, sometimes measured to evaluate thyroid function, particularly in complex cases of thyroid dysfunction.

These tests can be used in various combinations to diagnose hypothyroidism, hyperthyroidism, thyroiditis, and thyroid cancer, and to monitor thyroid replacement or suppressive therapy. The selection of specific tests usually depends on the clinical context and the information needed to guide diagnosis and treatment.