The clinicopathologic differences in papillary thyroid carcinoma with or without co-existing chronic lymphocytic thyroiditis.

The goal of this study is to determine the clinicopathologic differences in patients with papillary thyroid carcinoma (PTC) with or without chronic lymphocytic thyroiditis (CLT). We reviewed the medical records of 195 consecutive PTC patients who underwent total thyroidectomy and bilateral central lymph node dissection from April 2008 to March 2010. The differences in clinicopathologic factors, such as age, gender, size of primary tumor, perithyroidal invasion, lymphovascular invasion, capsular invasion, and central lymph node (CLN) metastasis, were analyzed in PTC patients with or without CLT. Among 195 patients, 56 (28.7%) had co-existing CLT. Patients with CLT had the following characteristics as compared to patients without CLT: significantly younger, female predominance, smaller tumor size, and lower incidence of capsular invasion (p = 0.038, 0.006, 0.037, and 0.026, respectively). Also, patients with CLT (12.5%) had a significantly lower incidence of CLN metastases than patients without CLT (28.1%; p = 0.025) based on univariate analysis. Moreover, multivariate analysis showed that younger age (p = 0.042, odds ratio = 1.033) and female gender (p = 0.012, odds ratio = 6.865) are independent clinical factors in patients with CLT compared to patients without CLT. CLT was shown to be commonly associated with PTC. Compared to patients with PTC without CLT, patients with CLT were younger with a female predominance, which are the most important and well-known prognostic variables for thyroid cancer mortality.