Clinical Features and Prognosis of Patients with Benign ThyroidDisease Accompanied by an Incidental Papillary Carcinoma

Purpose: To investigate the clinical features and prognosis of papillary thyroid carcinoma (PTC) with abackground of benign disease.
Method: A total of 709 patients with papillary thyroid carcinoma undergoingsurgical resection were analyzed retrospectively. In 147 patients who underwent surgery for benign thyroiddisease, incidental PTC (IPC group) were identified by intraoperative or postoperative pathological examinationof surgical specimens but were not detected by preoperative imaging studies. In the other group, according tothe pathological examination with or without co-existing benign thyroid disease, 253 cases were clarified asconcomitant PTC and 309 cases were clarified as dominant PTC.
Results: Incidental PTC was more commonin women, about 85.7%, the mean age was 47.6±11.3 years old. Average tumor diameter was 4.4±2.2 mm,multiple lesions accounted for 12.9% (19/147), and the cervical lymph node metastasis rate was 6.1% (9/147).After radical resection 8 cases recurred, the median time of recurrence was about 12 months (0.5 to 162), therewas no tumor-related death. The tumor-free survival rates were 97.3%, 95.9%, 91.5%, and 79.3% in 1, 5, 10and 14 year respectively.
Conclusion: Incidental PTC with a background of benign lesions is common, and thegenerally good prognosis can be attributed to tumor early detection and early treatment. On the intraoperativefinding of incidental PTC, lobectomy (unilateral) or total thyroidectomy (bilateral) should be the first choice, butwith a postoperative pathologic finding of incidental PTC, further treatment, such as completion thyroidectomyor immediate lymph dissection is not necessary. Central lymph node dissection is also not needed unlesslymphadenectasis is present.