Análise comparativa da incidência de câncer em pacientes operados com e sem hipertireoidismo

Introduction: The incidence of thyroid cancer in patients surgically treated for hyperthyroidism has increased in recent years. Most of these cases are composed of small tumors that are found only in the pathological analyze, which implies a big challenge for the head and neck surgeon. objective: To evaluate the relationship between hyperthyroidism and thyroid cancer. method: A retrospective study of patients operated in a single institution between 2004 and 2010. We identified 1133 patients underwent thyroidectomy of whom 761 cases were analyzed. Patients were divided into two groups, with and without diagnosis of hyperthyroidism. Chart review was performed with assessment of clinical and pathological variables. Statistical analysis of data was performed. Results: Among the patients studied, 8.3% had diagnosis of hyperthyroidism. Of these, 39.7% had Graves’ disease, 49,2% toxic multinodular goiter and 11.1% Plummer’s disease. The incidence of cancer was 20.6% in patients with hyperthyroidism and 38.7% in patients without (p=0.024). Patients with hyperthyroidism showed higher incidence of papillary thyroid microcarcinoma (p=0.011) and thyroiditis (p=0.02), lower sensitivity for detecting malignancy in fine needle aspiration (50%) and frozen section (25%). Most patients underwent total thyroidectomy, except for patients with Plummer’s disease (p<0.01). Conclusion: In our series the patients with hyperthyroidism had lower incidence of malignancy, and were mainly affected by papillary thyroid microcarcinoma. In most cases diagnose was done only in pathological analyses. Fine needle aspiration and frozen section examination showed low sensitivity for diagnosis of malignancy in this group.