[Thyroid cancer in patients with hyperthyroidism].

Objective: The prevalence of thyroid carcinoma in hyperthyroidism remains controversial. The aim of this retrospective study was to evaluate prevalence.
Patients and Methods: The prevalence of thyroid carcinoma was studied in 861 patients operated for clinical or infraclinical hyperthyroidism between 1992 and 1999. One hundred and fifty patients had a hot nodule, 13 of them with an associated goiter. Four hundred five patients had Graves' disease and 306 had a multinodular goiter. Multiple sections were made in all surgical specimens for pathology study.
Results: Prevalence in solitary nodules was 1.45%. For Graves' disease patients, it was 4.1%. Prevalence among patients with multinodular goiter was 4.9%. Among the cancers, 83% were microcarcinoma. Parathyroid morbidity after subtotal and total thyroidectomy was 0.56% and recurrent hyperthyroidism occurred in 1.6%.
Conclusions: These findings are grossly identical to those observed in simple, nontoxic diffuse multinodular goiter. It would therefore be difficult to incriminate hyperthyroidism as playing a causal role in the development of thyroid cancer. These results do however provide an argument favoring total or near total thyroidectomy when surgery is performed in patients with hyperthyroidism.