The relationship between chronic lymphocytic thyroiditis and central neck lymph node metastasis in North American patients with papillary thyroid carcinoma

Background. Several studies have reported that concurrent chronic lymphocytic thyroiditis (CLT) with papillary thyroid carcinoma (PTC) is associated with improved prognosis of the PTC, including decreased lymph node metastasis. We sought to assess the incidence of central nodal metastasis (CNM) in patients with PTC and concurrent CLT. Methods. We studied 495 consecutive patients who underwent thyroidectomy with nodal excision for PTC. Pathology reports identified the presence of CLT and the extent of CNM. Results. There were 226 patients (46%) with CLT and 220 (44%) with CNM. Patients with CLT were more often female (88% vs 71%; P < .001) and had a younger median age (43 vs 47 years; P = .03), a lesser incidence of CNM (35% vs 52.4%; P < .001), and a greater incidence of pT1a (40% vs 25%; P < .001) and pT1b (38% vs 29%; P < .001) tumors. Multivariate analysis showed that the presence of CLT was associated with a 39% decreased odds of CNM after adjusting for age, gender, tumor size, PTC histopathologic subtype, and presence of lymphovascular invasion (odds ratio, 0.61; 95% confidence interval, 0.38-0.99; P = .046). Predicted probability modeling showed that all females with CLT and no suspicious nodal findings on ultrasonography had a 9-11% risk of CNM with pT1a tumors. Conclusion. Female patients of all ages with CLT and small PTCs have the least incidence of CNM.