Incidental carcinoma of the thyroid.

The diagnosis of incidental thyroid carcinoma in patients submitted to thyroidectomy for a benign disease is quite frequent. A retrospective analysis was performed on 455 patients submitted to surgical intervention in order to establish the incidence of this kind of carcinoma. Two hundred fifty-six patients (56%) were affected by benign disease (176 multinodular goiter, 12 uninodular goiter, 1 Plummer disease and 67 Basedow disease) and 202 (44%) by carcinoma. In 28 of 256 patients (11%), affected by benign disease, occurred a histological diagnosis of thyroid carcinoma, (10 papillary carcinoma, 1 follicular carcinoma, 29 papillary carcinoma follicular variant). In this study it's considered incidental thyroid carcinoma the one occurred in patients who never underwent Fine Needle Aspiration (FNA) and there were no suspicious features in all exams that may suggest the presence of carcinoma. Twenty-three of the 40 incidental carcinoma (57.5%) were microcarcinomas. Ten patients had a sincronous carcinoma. Actually, these patients are still in a follow up program and no recurrency of disease is occasionally observed. This study shows that the only way to put doubts on the real benignity of the disease is the fine needle aspiration; there are no other instruments that could identify the occurrence of the carcinoma. Moreover in the majority of cases the incidental carcinoma is a microcarcinoma, it doesn't reach significant volume, may be not centered by a FNA, but in most cases it's not really biologically aggressive.