Prevalence of thyroid carcinoma in toxic goiter

The prevalence of thyroid carcinoma in a surgical series of 159 patients with toxic goiter, compared with a surgical series of 460 patients with non-toxic goiter, is reported. As regards the hyperthyroid group carcinoma was found in 8 patients (5.0%); specifically, a similar incidence occurred in nodular toxic goiter (NTG) (5 cases: 6.1%) and autonomously functioning single nodule (AFSN) (3 cases: 4.8%), whereas no malignancy was detected in patients with diffuse toxic goiter (DTG). In the euthyroid group, carcinoma was found in 56 patients (12.2%). The presence of carcinoma was unsuspected in all hyperthyroid patients and in 19 out of 56 euthyroid patients; the sex ratio indicated a strong female prevalence (F/M: 7/1); the age distribution did not differ from the whole thyrotoxic group. Pathology detected a papillary carcinoma in all patients, multicentric in one case. Follow-up ranged from 1 to 5 years; no recurrencies were evidenced. Our data agree with other recent reports about the coexistence of hyperthyroidism and thyroid carcinoma; still there are some controversies concerning the clinical significance of occult thyroid carcinoma, that apparently occurs with a similar rate in toxic goiter, in non-toxic goiter and in the general population.