Thyroid papillary carcinoma associated to Hashimoto's thyroiditis.

Unlabelled: There is controversy in the literature regarding the association between papillary thyroid carcinoma (PTC) and Hashimoto's thyroiditis (HT) and as to what would be the etiological relationship between them.

Objective: To establish the proportion of cases among patients with TH and CPT, correlating it with histomorphological aspects.

Method: A retrospective study of patients undergoing partial or total thyroidectomy for PTC between 2007 and 2009, a total of 41 cases.

Results: Regarding the association of HT and CPT, we found 11 cases (26.8%), all females, but without statistical significance. The mean age was 44.9 years among the patients with coexistent TH and CPT, whereas it was 49.1 years without that association. The average size of tumors in those without TH was 20.53 mm and for those with TH it was 12.72 mm (p = 0.4). Regarding pathology staging, the ratios between those with and those without TH were kept in T1a, T1b and T3. In T2, there were no cases of coexistence of HT and PTC.

Conclusion: There is a rate of 26.8% of patients with association between TH and CPT, but without differences in relation to tumor size.