Multinodular Thyroid Disease

Multinodular goitre is the most prevalent thyroid pathological abnormality worldwide, although its geographical incidence varies greatly according to environmental iodization Most countries in central and southern Europe have endemic goitre areas with a prevalence of multinodular goitre (MG) of 3-6%. In United States, the annual incidence of nodular thyroid disease is 0.1% to 1.5% and the prevalence is 4-7%. In older studies as in 1950’s in Framingham, Massachusets 1% of persons in the age 30-59 yrs had a multinodular goitre. In Whickham in northeast England, palpable goitres were detected in 10% of adult women and 2% of adult men Multinodular goitre refers to an enlargement of the thyroid with deformation of normal parenchymal structures by the presence of nodules. These nodules vary considerably in size, morphology and function. The development of nodular goitre is very likely a continuous process that starts with thyroid hyperplasia and simple goitre. The main epidemiological determinants are iodine deficiency, age, sex and duration of goitre in iodine deficient and also iodine sufficient areas. Thyroid nodules are discovered by palpation in 3-7% of the population. However on ultrasonography (US) it is noted in 20-76% and by autopsy in approximately 50%. Increasing use of high resolution ultrasonography (HRUSG) over the last two decades has lead to an increasing prevalence of thyroid nodules in asymptomatic subjects. Moreover, 20-48% of patients with single palpable thyroid nodule are found to have additional nodules when investigated by HRUSG. Prevalence increases linearly with age, exposure to ionizing radiation and iodine deficiency. Thyroid nodules are more common in women.