Hurthle Cell Carcinoma of the Thyroid Gland: Clinicopathologic Features and Treatment Outcome Compared with Pure Follicular Thyroid Carcinoma

Abstract

Purpose: Hurthle cell carcinoma (HCC) of the thyroid gland is a rare disease that represents 3% of all thyroid carcinomas. HCC has been known as a more aggressive disease than the usual differentiated thyroid carcinoma. However, the biologic behavior and optimal treatment have come under considerable debate in recent years. This study was performed to evaluate the clinicopathologic features and treatment outcome of HCC. Methods: From April 1986 to August 2006, 18 patients with HCC and 216 patients with pure follicular carcinoma (PFC) underwent thyroidectomy at our institutions with a mean follow-up of 114 (range: 6∼253) months. The clinicopathologic characteristics and treatment outcome of each group were compared, and the prognostic factors for disease-free survival were analyzed. Results: There were 14 women and 4 men with a mean age of 50 (range: 26∼76) years. Compared with PFC patients, all of clinicopathologic features of HCC patients were different (gender, age, tumor size, multifocality, angioinvaion, invasion to adjacent structures, the subclassification and ini-tial distant metastasis), but the high incidence of bilaterality was similar to the PFC patients (P＜0.0001). The cause- specific survival (CSS) rates at 10 years were 83.4% in the HCC patients and 89.3% in the PFC patients (P=0.702). Older age (greater than 45) (P=0.0125) and initial distant metastasis (P＜0.0001) in the HCC patients, and an older age (P＜0.0001), male gender (P=0.0039), angioinvasion (P= 0.0122), invasion to adjacent structures (P＜0.0001), a widely invasive type (P=0.004) and initial distant metastasis (P＜0.0001) in the PCC patients were independent prognostic factors for survival. Conclusion: After accounting for important biologic behaviors, patients with HCC had similar clinicopathologic characteristics and prognosis compared with that of the PFC patients. Therefore, HCC should be managed using the same treatment strategy as PFC.