Benign Thyroid Disease

49 Benign Thyroid Disease


49.1 Clinical Features


• Multinodular, simple (smoothly enlarged), retrosternal goitres


• Increased where iodine is deficient


• Long-standing may develop clinical or subclinical thyrotoxicosis


• Symptoms


figure Neck swelling


figure Dyspnea


figure Dysphagia


figure Choking


figure Stridor


49.2 Epidemiology


• Ethnicity


figure No racial predilection exists


• Incidence


figure Multinodular goitres is one of the common endocrine conditions, affecting 500 million people worldwide


• Sex


figure F:M 5:1


figure In the Wickham study, 26% of women had a goitre compared with 7% of men


figure Thyroid nodules are less frequent in men than in women, but when found, they are more likely to be malignant


• Age


figure The frequency of goitres decreases with advancing age


figure The decrease in frequency differs from the incidence of thyroid nodules, which increases with advancing age


• Aetiology


figure Iodine deficiency


figure Autoimmune thyroiditis—Hashimoto or postpartum thyroiditis


figure Excess iodine (Wolff–Chaikoff effect) or lithium ingestion, which decrease release of thyroid hormone


figure Goitrogens, e.g., propylthiouracil, lithium, carbamazepine


figure Stimulation of thyroid stimulating hormone (TSH) receptors by TSH from pituitary tumours, pituitary thyroid hormone resistance, gonadotropins, and/or thyroid-stimulating immunoglobulins


figure Inborn errors of metabolism causing defects in biosynthesis of thyroid hormones


figure Exposure to radiation


figure Deposition diseases


figure Thyroid hormone resistance


figure Subacute thyroiditis (de Quervain thyroiditis)


figure Silent thyroiditis


figure Riedel thyroiditis


figure Infectious agents


– Acute suppurative—bacterial


– Chronic—mycobacteria, fungal, and parasitic


figure Granulomatous disease


figure Thyroid malignancy


49.3 Simple Goitres (Fig. 49.1)


• Physiological


figure Puberty


figure Pregnancy


figure oral contraceptive pill (OCP)


• Pathological—iodine deficiency


• Medical treatments


figure Radioactive iodine:


– Up to 50% reduction in goitre volume


– Risks include: hypothyroidism, Graves


– Contraindicated in pregnant women or women wanting to get pregnant within 1 year of treatment


figure Suppression therapy:


– Thyroxine administration decreases TSH leading to a reduction in volume


– Risks include: thyrotoxicosis, cardiac arrythmias, thyroid increases to pretreatment size on cessation of thyroxine, osteopenia in long-term thyroxine use


figure Antithyroid medication:


– Indicated for thyrotoxic patients, e.g., propylthiouracil (side effects: rash and agranulocytosis)


– 50% relapse rate


• Retrosternal goitre


figure May present with dyspnea, stridor that is positional/nocturnal, or coincidentally on chest X-ray with shadowing in upper mediastinum


figure Clinically:


– Inability to palpate below it


– Dullness to percussion over sternum


– May only be a small cervical component


– Pemberton sign: facial flushing after raising both arms in the air due to compression of jugular veins by thyroid


figure Investigations:


– CT scan good for demonstrating retrosternal extent ± tracheal compression


– Spirometry


figure Treatment:


– Conservative (if medically unfit)


– Surgery: most can be removed via cervical route (unless below aortic arch) may need cardiothoracic input ± sternotomy


– Increasing role of radioactive iodine in euthyroid retrosternal goitre safe to use down to a tracheal diameter of 1 cm


49.3.1 Toxic Goitres


49.3.2 Clinical Features


• Graves disease


figure Most common


figure One or more:


– Thyrotoxicosis


– Goitre


– Eye signs: lid lag, exophthalmos, chemosis


– Skin signs: acropachy, pretibial myxedema


figure Autoimmune with thyroid antibodies


figure 15% family history


figure F>M 5:1; middle ages


figure Treatments:


– Radioactive iodine


– Antithyroid drugs, e.g., carbimazole or propylthiouracil


– Block and replace: antithyroid drugs full dose + thyroxine to replace thyroid function


– Surgery


• Solitary toxic nodule


• Long-standing MNGs (Plummer disease)


49.3.3 Treatment


• 50% of patients relapse on carbimazole/propylthiouracil—may request thyroidectomy


• When considering surgery need to achieve euthyroid state preop with antithyroid medication, β-blockade and Lugol iodine (up to 2 weeks preop)



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Jul 4, 2016 | Posted by in OTOLARYNGOLOGY | Comments Off on Benign Thyroid Disease

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