[Post-operative hypothyroidism]

Hypothyroidism is not a rare condition, since it represents about 10% of thyroid diseases. It is more frequent in women (F/M = 5/1), and in patients older than 60 years of age. Postoperative hypothyroidism is secondary to thyroidectomy, and the incidence varies, with a reported range between 14% and 75%. This may be related to the amount of thyroid removed, the experience of the surgeon, age of patient, the function of remaining thyroid, and duration of postoperative observation. The analysis of our cohort of more than 23,000 thyroid patients showed a prevalence of hypothyroidism of 11.1%. Postoperative hypothyroidism represents about 39.7% of all hypothyroid cases, and 44% of patients underwent surgery. The prevalence is six fold higher in patients over the age of 60. Factors favoring development are the presence of lymphocytic infiltration of the thyroid and a positive serological test for thyroid antibodies. Overt hypothyroidism represented the largest proportion, prevailing in 60% of postoperative hypothyroid patients. In view of the insidious development of postoperative hypothyroidism in some patients, an accurate follow-up should be required, allowing an opportune treatment with LT4.