This prospective study included 112 patients managed with total thyroidectomy in KasrAl-Aini hospital, Cairo University between May 2016 and 2018. All methods were carried out in accordance with relevant guidelines and regulations. Study protocol was approved by the Institutional Review Board of Cairo University Hospitals. Informed consent was obtained from all subjects included in the study
All patients presented to the endocrine and metabolism outpatient clinic complaining of nodular thyroid swelling that was proved to be non-malignant. Patients who were thyrotoxic or on thyroxine, on anti-thyroid drugs, steroids, or immunosuppressive drugs were excluded.
All included patients have positive anti TPO ab with or without positive anti TG ab
All patients are euthyroid before surgery. In the department of surgery, all patients were subjected to total thyroidectomy after proper pre-operative preparation. Thyroidectomy was done for cosmetic purposes, to alleviate pressure symptoms, or for suspected malignancy. Operations were done using standard transverse neck incision. Dissection was done taking care not to injure parathyroid glands or recurrent laryngeal nerve. Suction drain insertion was performed when indicated.
Weight-based L-thyroxin(1.4–1.6 microgm/kg) is prescribed to all patients postoperatively with dose adjustment based on target TSH level.
All patients were subjected to throughout history taking, general and local examination. Laboratory assessment included TSH, freeT4,T3, antithyroid peroxidase(TPO-Ab), and antithyroglobulin (Tg-Ab). All patients were assessed with Ultrasonography of the neck region.
Anti TPO-Ab levels > 40 IU/mL were considered TPO-Ab-positive,andthose with Tg-Ab levels > 20 IU/mLwere considered Tg-Ab-positive 
Antibody negative patients were excluded from the study.
Some patients (n = 55) (solitary, ithmic or dominant nodules with suspicious criteria) had fine needle aspiration cytology (FNAC)of thyroid nodule.
Thyroidectomy specimens were subjected to histopathological examination using H and E stains. Both FNAC and postoperative specemins are examined at kasrelaini pathology departement.
Postoperatively, laboratory assessment was repeated after 6 and 12 months. This included TSH,freeT4,T3, TPO-Ab, and Tg-Ab.Patients with TPO-Ab levels > 40 IU/mL were considered TPO-Ab-positive,andthose with Tg-Ab levels > 20 IU/mLwere considered Tg-Ab-positive .
Statistical analysis was done using IBM© SPSS© Statistics version 22 (IBM© Corp., Armonk, NY, USA). Numerical data were expressed as mean and standard deviation or median and range as appropriate. Qualitative data were expressed as frequency and percentage. Chi-square test was used to examine the relationship between qualitative variables.For quantitative data, a comparison between two groups was made using independent sample t-test or Mann-Whitney test. Comparison between 3 groups was made using ANOVA test, or Kruskal-Wallis test followed by the appropriate post-hoc test. Comparison of repeated measures was made using Friedman test followed by Wilcoxon signed-ranks test. A p-value < 0.05 was considered significant.