Thyroid carcinoma and hyperthyroidism

The present study is a retrospective evaluation of a consecutive series of 183 hyperthyroid patients surgically treated at our department from January 1988 through December 1993. In 10 cases, with an overall cancer incidence of 5.4%, a differentiated thyroid carcinoma was occasionally diagnosed; more in detail, a neoplasm occurred in 6 cases of nodular toxic goiter (specific incidence: 6.5%), in 3 cases of autonomously functioning single nodule (specific incidence: 4.1%) and in 1 case of diffuse toxic goiter. pathology showed evidence of cancer in 3 cases at intraoperative frozen section, whilst the diagnosis was reached postoperatively in the remaining 7 cases; a papillary carcinoma was detected in 9 patients and a follicular microcarcinoma in 1 patient. Mean follow-up is 25.6 months (range: 6-60 months): up to date all patients are alive and with no evidence of cancer recurrence. Our retrospective study is on the same line with the recent literature showing, in the last 2 decades, a progressive increase of the association between hyperthyroidism and cancer. It has not been definitely clarified if this should be considered statistically significant or simply related to diagnostic improvements and extended surgical indications in thyrotoxic patients; moreover the clinical implications of occasional diagnosis of differentiated microcarcinoma of the thyroid are still matter for debate. The occurrence of a malignancy during the clinical course of a hyperthyroidism should anyway be considered more cautiously than in the past. According to the different epidemiologic, pathologic and clinical patterns of a differentiated carcinoma in the various forms of hyperthyroidism, a modulated strategy for surgical approach is suggested.