Endocrine Abstracts

Introduction: The association of hyperthyroidism and thyroid cancer (TC) is controversial with prevalences in the literature varying from 1.6 to 32.8%. The aim of this work was to evaluate the prevalence of TC in hyperthyroid patients submitted to surgery and to find differences between the tumors according to the type of hyperthyroidism.

Material and methods: retrospective study to evaluate clinical and histopathological data of all hyperthyroid patients older than 18 years that underwent thyroid surgery between 2005 and 2015 at our Hospital. Statistics was done with SPSS 22.0 for windows.

Results: In this period 413 hyperthyroid patients were submitted to surgery, 347 females and 66 males, 108 (26.2%) with Graves Disease (GD), 263(63.7%) with Multinodular Toxic Goiter (MNTG) and 42 (10.2%) with Toxic Adenoma (TA). Concerning sex distribution there was no statistical difference between the 3 groups. The mean age in GD was significantly lower than in TMNG (43.9±13.2 vs 58±13.9 years) and in TA (43.9±13.2 vs 50.5±16.2 years). Histologic examination revealed TC in 89 patients (21.5%) with mean diameter of the tumors of 0.88 cm (0.1–6.5 cm). The majority of the tumors were incidental findings (82%). Concerning the type of surgery performed, total thyroidectomy was more frequent in GD and TMNG compared to TA (97.2% and 94.7% respectively vs 21.4%).The prevalence of TC was 25.1% for TMNG, 16.7% for GD and 11.9% for TA. Histopathology examination revealed Papillary thyroid cancer in the majority of cancer patients, 16/18 (88.9%) in GD, 60/66 (90.9%) in TMNG and 4/5 (80%) in TA. There were no significant differences in tumor size, incidental finding, presence of thyroiditis, extrathyroidal extension, lymphovascular invasion and ganglionar metastasis between the 3 groups.

Conclusion: In our series we found a high prevalence of TC in hyperthyroid patients (21.5%), higher than the majority of the series in the previous literature.