[Clinico-pathological features of papillary thyroid cancer coexistent with Hashimoto's thyroiditis].

Introduction and aim: Former studies suggest the frequent coexistence of Hashimoto ' s thyreoditis with papillary thyroid cancer, frequently featured by multifocal carcinogenesis but lower clinical stages compared to thyroid cancers lacking thyroiditis. We examined the clinico-pathological correlations between Hashimoto ' s thyroditis and papillary thyroid cancer in our region in the North-Eastern part of Hungary. Patients and method: We included a total of 230 patients with papillary thyroid cancer who underwent thyroid surgery at the Surgical Department of the University of Debrecen. Patients ' sex, age, multifocality of thyroid cancer and clinical stage were evaluated. Results: Cases included 40 patients (17.4%) with (4 male, 36 female) and 190 (82.6%) patients without HT (44 male, 146 female). Hashimoto's thyroiditis related thyroid cancer was almost exclusively associated with the papillary histological type. Multifocality of papillary cancer was significantly more frequent with coexisting Hashimoto's thyroiditis (16/ 40; 40.0%) compared to cases uninvolved (45/190; 23.7%; p = 0.034). In contrast, lymph node metastasis was significantly less frequent among patients with Hashimoto's thyroiditis (4 pN1 [36.4%]; 7 pN0 [63.6%]) then without it (34 pN1 [82.9%]; 7 pN0 [17.1%]; p = 0.002). Conclusion: Higher frequency and multifocality of papillary thyroid cancer might be the consequence of preexisting Hashimoto's thyroiditis to be considered as a preneoplastic stimulus supporting carcinogenesis, though the exact pathomechanism of this correlation is not clear yet.