The relation of goitre size measured by ultrasonography with age at presentation (panel a) and with duration of goitre (panel b) in 102 consecutive patients with sporadic non-toxic goitre. Reproduced from Berghout A, Wiersinga WM, Smits NJ, Touber JL. Interrelationships between age, thyroid volume, thyroid nodularity, and thyroid function in patients with sporadic non-toxic goiter. American Journal of Medicine, 1990; 89: 602–8, with permission.