Thyroid carcinoma in thyrotoxic patients treated by surgery

We report the incidence of thyroid cancer in a series of 1832 consecutive patients seen for thyrotoxicosis of any etiology during 1970 and 1985 in our department. Surgical treatment for thyrotoxicosis was selected as the treatment of choice in 179 patients (9.8%), 86 with toxic diffuse goiter (TDG), 21 with toxic nodular goiter (TNG) and 40 with toxic adenoma (TA). The presence of thyroid cancer was found in 11 patients for a total incidence of 6.1%. Six patients had TDG (percent incidence in this group 6.9%), 4 patients had TNG (7.5%) and 1 had TA (2.5%). While the presence of thyroid cancer was totally unsuspected in TNG and TA, in TDG 4 out of 6 patients found to have a cancer, had been suspected before surgery. When a thyroid nodule was present in a toxic diffuse goiter the possibility to face with a malignant lesion reached 22.2% of the cases (4 out of 18 cases), while only 2 out of 68 patients (2.9%) with TDG and no nodule had thyroid cancer. These results confirm recent other series reporting the frequent association of hyperthyroidism and thyroid cancer and suggest that in thyrotoxic patients any nodule must be screened carefully to rule out malignancy.