Despite improved preoperative diagnostics, incidental postoperative detection of differentiated thyroid cancer in the final histology is still common. In most of these cases, completion thyroidectomy is recommended by national and international guidelines, although secondary surgery is associated with an increased operative risk. The optimal timing of completion thyroidectomy is still controversial.

The patients admitted to surgical oncology department, SECI, with diagnosis of differentiated thyroid cancer; during the period from January 2008 to December 2015; were rewired for age, sex, type of 1st operation, histopathological result, type of 2nd operation and time interval between the 2 operation, complication of 2nd operation and morbidity. 118 patients underwent completion thyroidectomy; those patients were divided according to timing of completion operation into 3 groups: Group A is from one week to 3 months and include 64 patients; Group B is from 3 - 6 months and include 30 patients; Group C is more than 6 months and include 24 patients. Clinical complications and oncologic outcomes were analyzed. The mean follow-up was 80 ± 10 months.

we record 118 patients under completion thyroidectomy. Ages range from 79 to 13 years. Papillary thyroid cancer were 96 and follicular thyroid cancer were 22. The overall rates of transient and persistent postoperative hypocalcemia were 19.5% and 4.2%, respectively. The rates of persistent hypocalcemia were found in group A and B but not in group C. Transient or persistent vocal cord paresis was observed in 9 (7.6%) and 3 patients (2.5%). The incidence of persistent vocal cord paresis (VCP) was significantly higher in groups A and B than in group C. There was no significant difference regarding survival among the 3 groups; however recurrence is higher in group A.

Considering perioperative morbidity and oncologic outcomes, completion thyroidectomy should be performed at least 3 to 6 months after primary surgery.