High risk for microcarcinoma in thyroid benign diseases. Incidence in a one year period of total thyroidectomies

Over the last few years, incidental thyroid microcarcinoma (TMC) has become a frequent disease and its incidence in some reports is considerable. The discovery of new cases depends on the progress of the diagnostics (US scan, fine needle biopsy and cytology, CT, MRI), on the extended indications to thyroidectomy for benign disease and on the attention in pathologic examination of the specimen. The clinical evolution of this disease is not well known: in spite of a high incidence reported in some autoptic series, suggesting that this tumour could have a good prognosis, some authors report an overall incidence of up to 11% of local recurrence, metastasis and mortality. For these reasons the treatment of TMC is still controversial today. Aim of this study was to estimate the incidence and the clinico-pathological findings of TMC over a one year period of total thyroidectomies for diffuse benign thyroid diseases, and to evaluate, on the basis of the frequency of incidental microcarcinoma, if the surgical procedure of complete removal of the gland should be adopted in any case. In this series no patient had pre-operative diagnosis or tentative diagnosis of carcinoma and the incidence of TMC at the final histologic examination was 27.4%. Total thyroidectomy confirmed to be the treatment of choice for diffuse benign diseases and appeared necessary to obtain both, diagnosis and treatment of incidental TMC.