Differentiated thyroid carcinoma recurrence: patterns and participating factors

Background Surgery for recurrent differentiated thyroid carcinoma is technically difficult, is demanding, and carries a higher risk for complications than de novo cases, so understanding the precipitating factors and patterns of recurrence will help in practicing maneuvers that can help in decreasing the recurrence. In this study, we examined these factors and patterns of recurrence. Patients and method A total of 40 patients with recurrence after differentiated thyroid carcinoma surgery were subjected to redooperations after clinical evaluation and all needed preoperative investigations. Preoperative and operative data and postoperative surgical and pathological outcomes were collected and analyzed. Results Our results revealed that the size of the primary tumor had a negative or inverse significant relationship with time passed till occurrence of recurrence or relapse (P=0.044). However, postoperative radioactive iodine therapy, postoperative thyroxine replacement therapy, unifocal tumors, and total thyroidectomy in primary procedure all were associated with a wider range of recurrence time with a higher mean +/- SD but did not reach a statistically significant level. Central compartment lymph nodes are the most affected group (95%) followed by level IV nodes, which had a 100% correlation with central group, and all lateral groups summed 82.5%. Conclusion The primary tumor size has a significant inverse relationship with time till occurrence of relapse. However, other factors did not reach a statistically significant level. Central compartment lymph nodes, which are very difficult for safe dissection in recurrent cases, are the most affected group, confirming being the first echelon nodes followed by level IV nodes. Therefore, prophylactic routine meticulous central dissection in the primary cases is advised for being much easier and safer.