The effect of chronic lymphocytic thyroiditis on patients with thyroid cancer

Background The purpose of this study was to investigate the association between chronic lymphocytic thyroiditis (CLT) and malignant tumors of the thyroid. Methods A retrospective review of 647 patients who underwent thyroid surgery at the Department of Breast and Thyroid Surgery in Anhui Provincial Hospital, China in 2012 was performed. The clinicopathological characteristics of patients with thyroid malignancies and CLT were collected. CLT was diagnosed by histopathological method. Results Among 647 patients, 144 patients had thyroid malignancies and 108 patients had been diagnosed with CLT. Moreover, in total, 44 patients had thyroid malignancies coexistent with CLT: forty-one (93.2%) patients had been diagnosed with the papillary thyroid cancer (PTC); two (4.5%) patients suffered from medullary carcinoma; and one (2.3%) patient suffered from lymphoma. The morbidity of thyroid malignancies in patients with CLT was significantly higher than that in patients without CLT (40.7% versus 18.6%; P <0.001). A female preponderance was observed in the patients with CLT compared with those without CLT ( P <0.001). There was no statistically significant difference in the tumor size ( P = 0.073), multifocality ( P = 0.0871), neck lymph node metastasis ( P = 0.350), age ( P = 0.316), microcarcinoma ( P = 0.983) and tumor-node-metastasis (TNM) stage ( P = 0.949) between the patients of thyroid malignancies with CLT and without CLT. Conclusions Female predominance was observed in patients with CLT. CLT may have no effect on the progression of thyroid malignant tumor. Nevertheless, the influences of CLT on the prognosis of the thyroid carcinoma still need to be investigated with a larger sample size.