Effects of chronic lymphocytic thyroiditis on the clinicopathological features of papillary thyroid cancer

Abstract

Background: The effects of chronic lymphocytic thyroiditis (CLT) on the presentation and outcome of papillary thyroid carcinoma (PTC) have long been a topic of controversy. Objective: To evaluate the effect of coexistent CLT on the clinicopathological features of PTC. Design: Retrospective study. Patients: All patients with PTC who had been followed by the 2 co-investigators (Juan Rivera and Richard J. Payne) between 2006 and 2011 were included. Results: CLT was present in 35% (166) of the included patients and was associated with a higher proportion of patients with TNM stage I (p = 0.027) and fewer patients with persistent disease (p = 0.014) in comparison with the PTC-only group. Analysis of the data based on age (<45 or >45 years) revealed that in the older group, the presence of CLT was associated with fewer patients with persistent disease (p = 0.03) and capsular invasion (p = 0.05). However, in patients <45 years of age, the presence of CLT was associated with more capsular invasion (p = 0.003) and extrathyroidal extension (p = 0.004) compared with the PTC-only group. Conclusions: CLT in patients with PTC was associated with lower-stage disease and less disease persistence in patients >45 years of age. In patients <45 years, the presence of CLT appeared to be associated with unfavorable pathological features.