The study of the coexistence of Hashimoto's thyroiditis with papillary thyroid carcinoma

Abstract

Purpose: Hashimoto's thyroiditis (HT) is the most common type of autoimmune thyroid disease, and the incidence is rising in recent years. The aim of this study was to evaluate the pathological characteristics, treatment and prognosis of HT with papillary thyroid carcinoma (PTC).

Methods: From July 2004 to December 2011, 8,524 patients underwent thyroid surgery in our hospital and 1,735 patients were diagnosed with PTC. The data from these patients were statistically analyzed using SAS software.

Results: There were 839 patients with a final diagnosis of HT in this study. A greater incidence of PTC was found in those with HT (29.4 %) than those without HT (19.4 %; p < 0.05). Male HT patients had a significantly higher rate of PTC (27/61, 44.3 %) when compared to female patients (220/778, 28.3 %; p < 0.05). The HT patients with co-occurring PTC were more likely to be younger (43.1 vs. 46.6, p < 0.01) and had smaller nodules (1.10 vs. 1.34 cm, p < 0.05), less external invasion (0.4 vs. 2.5 %, p < 0.05), less lymph node metastasis in lateral neck area (17.2 vs. 26.9 %, p < 0.05) and less advanced TNM stages than PTC patients without HT.

Conclusions: Hashimoto's thyroiditis is associated with a significantly higher risk of PTC, and the incidence of PTC is much higher in male HT patients. More attention should be paid to HT patients, especially male HT patients, for signs of PTC. Based on the less aggressive pathological features in HT-PTC group, we should not blindly expand the indication and extent of surgery.

Fig. 1

Pathological characteristic of HT, PTC and coexistence of HT with PTC. a There are rich colloid and epitheliums in normal thyroid tissue. b There are a large number of lymphocytic infiltrations in the thyroid tissue of HT. c Dysplastic cells arrange as fingers or papillas in the thyroid tissue of PTC. d Both infiltration of lymphocyte (white triangle) and dysplastic cells (black triangle) can be observed simultaneously in the thyroid tissues of coexistence of HT with PTC