Definition of  goitre : 

Goitre : The normal thyroid gland is impalpable. The term goitre (from Latin guttur = the throat) is used to describe generalized enlargement of the thyroid gland.

• A discrete swelling (nodule) in one lobe with no palpable abnormality elsewhere is termed as isolated (or solitary) swelling.
• Discrete swelling with evidence of abnormality elsewhere in the gland is termed dominant.

Classification of goitre / thyroid swelling :

Simple goitre : 

• Diffuse hyperplastic goitre
• Physiological
• Pubertal
• Pregnancy

• Multinodular goite

Toxic goitre :

• Diffuse toxic goitre (Grave’s disease)
• Multinodular goitre
• Toxic adenoma

Neoplastic goitre :

• Benign
• Malignant

Inflammatory goitre :

Autoimmune :

• Chronic lymphocytic thyroiditis
• Hashimoto’s thyroiditis

Granulomatous :

• De Quervain’s thyroiditis

Fibrosing : 

• Riedel’s thyroiditis

Infective : 

• Acute (Bacterial thyroiditis, viral thyroiditis, sub-acute thyroiditis)
• Chronic (tuberculous, syphilitic)

Other :

• Amyloid

Define simple goitre :

Simple goitre : Simple goitre may develop as a result of stimulation of the thyroid gland by TSH, either as a result of inappropriate secretion from a microadenoma in the anterior pituitary (which is rare), or in response a chronically low level of circulating thyroid hormones.

Causes of simple goitre :

• lodine deficiency (Endemic)
• Enzyme deficiency (Sporadic).
• Presence of goitrogens in diet.

Stages of multinodular goitre :

Stages in goitre formation are:

Persistent TSH stimulation – Diffuse hyperplasia of gland (all active lobules) – Later with fluctuation of TSH level – Mixed areas of active and inactive lobules develop. It is also probably due to increased sensitivity of follicular cells to TSH –  Haemorrhages occur with necrosis in the – Nodule formation – Centre of the nodule is inactive and only margin is active, i.e. internodular tissue is active – Formation of many nodules – Multinodular goitre (MNG)

Other factors involved are growth stimulating immunoglobulins and growth prone cell clones.

Complications of long standing multinodular goitre :

1. Secondary thyrotoxicosis (30%).
2. Follicular carcinoma of thyroid.
3. Haemorrhage.
4. Tracheal compression.
5. Tracheal obstruction.
6. Tracheal calcification.
7. Cosmetic problem.

Management of simple goitre :

Diagnosis of simple goitre : 

1. Straightforward diagnosis
2. Patient is euthyroid.
3. The nodules are palpable and often visible.
4. Nodules are smooth, usually firm and not hard.
5. The goitre is painless and moves freely on swallowing
6. Hardness and irregularity, due to calcification, may simulate carcinoma.
7. A painful nodule, sudden appearance, or rapid enlargement of a nodule raises spicion of carcinoma but is usually due to haemorrhage into a simple nodule.

Investigations of simple goitre :

1. Thyroid function test: T,, T, & TSH.
2. Ultrasound is the gold standard.
3. FNAC (ultrasound guided is ideal).
4. Ultrasound guided biopsy.
5. CT scan of the thoracle inlet. If there is swallowing or breathing symptoms.

Treatment simple goitre :

• In endemic areas : The incidence of goitre has been strikingly reduced by the introduction of iodized salt.
• In the early stages : Hyperplastic goitre may regress if thymine is given in a dose of 0.15-03 mg daily for a few months.
• Although the nodular stage of simple goitre is imeversible, more than half of benign nodules will regress in size over ten years.
• Most patients with multinodular goitre are asymptomatic and do not require operation.

Surgery :

Consideration of surgery :

1. Cosmetic purpose
2. Patient wish
3. Pressure symptons
4. Carcinomatous changes.

Options :

• Total thyroidectomy
• Subtotal thyroidectomy