Endocrine Abstracts

Background: The main objective of this study is to establish the rate of malignancy in residual thyroid tissue in patients with DTC, and whether the serum thyroglobulin (Tg) level before complementary thyroidectomy and histopathologic characteristics of the tumor would be able to foresee malignancy in residual tissue.

Methods: Our study included 58 patients with DTC that underwent complementary thyroidectomy that results were analyzed retrospectively. Patients were then divided into two groups as patients that were established to have tumor in residual tissue (group 1) and not to have tumor in residual tissue (group 2) based on the pathology findings of residual tissue following complementary thyroidectomy. Both groups were compared in terms of serum Tg levels before complementary thyroidectomy and histopathologic characteristics of tumor.

Results: Fifty three patients were found to have papillary thyroid cancer and five had follicular thyroid cancer. Median tumor diameter was 0.8 cm (0.1–5.5 cm), 16 patients (27.6%) was found to have multifocality, 4 patients (6.9%) had perithyroidal invasion, 16 patients (27.6%) had capsular invasion, and 7 patients (12.1%) was established to have vascular invasion. Following the complementary thyroidectomy, 13 patients (22.4%) out of 58 patients with DTC were found to have malignancy in residual tissue. A statistically significant difference was not observed between the two groups in terms of gender, age, serum Tg level before complementary thyroidectomy, type of tumor pathology, tumor size, bilaterality multifocality, arterial invasion, capsular invasion, and extrathyroidal invasion presence (P>0.05).

Conclusions: Factors that enable foreseeing malignancy in residual thyroid tissue are not completely known. In our study, we established that serum Tg level before complementary thyroidectomy and histopathologic characteristics of tumor does not have a predictive value in foreseeing malignancy in residual thyroid tissue; however, other studies containing more patients are of necessity to clarify the issue.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.