RESUMEN
INTRODUCTION: Hürthle cell carcinoma (HCC) is an uncommon thyroid cancer historically considered to be a variant of follicular thyroid carcinoma (FTC). The aim of this study was to assess the differences between these groups in terms of clinical factors and prognoses. PATIENTS AND METHODS: A total of 230 patients (153 with FTC and 77 with HCC) with a median follow-up of 13.4 years were studied. The different characteristics were compared using SPSS version 20 statistical software. RESULTS: Patients with HCC were older (57.3±13.8 years vs. 44.6±15.2 years; P<.001). More advanced TNM stages were also seen in patients with HCC and a greater trend to distant metastases were also seen in patients with HCC (7.8% vs. 2.7%, P=.078). The persistence/recurrence rate at the end of follow-up was higher in patients with HCC (13% vs. 3.9%, P=.011). However, in a multivariate analysis, only age (hazard ratio [HR] 1.10, confidence interval [CI] 1.04-1.17; P=.001), size (HR 1.43, CI 1.05-1.94; P=.021), and histological subtype (HR 9.79, CI 2.35-40.81; P=.002), but not presence of HCC, were significantly associated to prognosis. CONCLUSION: HCC is diagnosed in older patients and in more advanced stages as compared to FTC. However, when age, size, and histological subtype are similar, disease-free survival is also similar in both groups.