Endocrine Abstracts

Objective: Incidence of concomitant thyroid cancer and Hashimoto thyroiditis (HT) is found to be 0.3–58% in different series. In this study, we aimed to find out HT incidence in thyroid cancer patients in our clinic and we tried to determine ultasonographic and histopathologic features of tumor in these patients.

Method: About 165 patients diagnosed with thyroid carcinoma between 2005 and 2008 were included in the study. Patients with Graves’s disease were excluded. Preoperative and postoperative datas were evaluated retrospectively.

Results: Patients were grouped into 2 according to the presence of HT histopathologically. In Group I HT was not detected and 129 patients were in this group. Of these, 112 were female and 17 were female with mean age of 46.28±10.86. In this group, mean antithyroidperoxidase antibody (anti-TPO) was 34.59±69.16 IU/ml (0–35 IU/ml) and mean antithyroglobulin antibody (anti-TG) was 82.67±207.42 IU/ml (0–40 IU/ml). In Group II HT was present with thyroid carcinoma and there were 36 (21.8%) patients in this group. About 34 of these patients were female and 2 were male, mean age was 42.86±12.67. Mean anti-TPO and anti-TG antibody were 272.83±329.59 IU/ml and 442.32±826.5 IU/ml, respectively. Nodule features in ultrasonography were compared in two groups. There was no statistically significant difference between two groups in regard of echogenity, microcalcification, macrocalcification, halo sign and margin irregularity (P>0.05). Additionaly, histopathologically, tumor diameter, presence of capsule invasion and vascular invasion, multifocality were similar in two groups (P>0.05). Nonetheless, extrathyroidal invasion was found to be more in HT patients (P=0.023). Also, thyroid autoantibodies were significiantly higher in this group (P<0.001).

Conclusion: In this study we found HT in 21% of thyroid carcinoma patients. Besides, we concluded that presence of HT has no effect on ultrasonographic appearence of nodules. However, histopathologically in patients with HT, extrathyroidal invasion was more common. This result suggests that tumors may behave more aggressive in the presence of HT.