[Differentiated thyroid carcinoma and hyperthyroidism: a frequent association?]

The relationship between hyperthyroidism and thyroid carcinoma remains controversial. In hyperthyroid patients the incidence of thyroid cancer varies considerably from 0.1% to 21%. We analyzed the frequency of coexisting hyperthyroidism and thyroid malignancy in our experience. From September 2002 to June 2004, 450 patients were submitted to total thyroidectomy in our surgical department. Hyperthyroidism was observed in 71 cases and thyroid carcinoma in 110 (107 differentiated). The association of hyperthyroidism and thyroid cancer was observed in 15 patients (14% of differentiated carcinomas and 21.1% of hyperthyroid patients). All patients were submitted to total thyroidectomy and are alive and disease-free. Seven cases of transitory hypoparathyroidism were observed (46.6%). There was no other morbidity. The association of thyroid cancer and hyperthyroidism is by no means rare. Careful exami- nation of hyperthyroid patients is always necessary to exclude the presence of carcinoma. These results confirm that the operation should be total thyroidectomy when surgery is performed in patients with hyperthyroidism.