INTRODUCTION AND OBJECTIVE: The association between papillary thyroid carcinoma and its variants and Hashimoto's thyroiditis is widely questioned in the scientific area, as they both share several morphologic, immunohistochemical and biomolecular aspects. Thyroid tumors represent over 90% of all endocrine cancers and are characterized by genetic changes involving RET (rearrangements) and BRAS, RAS, P53 (mutations). Whereas Hashimoto's thyroiditis is an autoimmune disease characterized by auto-immune destruction followed by thyroid failure and it presents RET/PTC, RAS and FAS alterations. This study aims to describe the association of Hashimoto's thyroiditis with papillary carcinoma thyroid, correlating them with demographic data and histological variants. METHODS: It was conducted a case series study of 466 patients diagnosed with thyroid papillary carcinoma from January 2000 to December 2008. Case forms were filled up with the aim to collect demographic data and histological variants. RESULTS: The present study showed a coexistence of 30% of Hashimoto's thyroiditis in patients with papillary thyroid carcinoma. Among female patients there was a higher number of Hashimoto's thyroiditis cases, p = 0.046. CONCLUSION: The case series study showed a frequency of 30% of Hashimoto's thyroiditis in cases with papillary thyroid carcinoma suggesting a noncoincidental association, which raises the possibility of a cause and effect relation between thyroiditis and carcinoma development.
Thyroid; Pathology; Carcinoma; Thyroiditis; Hashimoto
