Preoperative BRAF Mutation is Predictive of Occult Contralateral Carcinoma in Patients with Unilateral Papillary Thyroid Microcarcinoma

Thyroid cancer is the most common endocrine malignancy, accounting for 1% of all malignant tumors in the USA (Sherman, 2003) and 5.9% in one district of Wenzhou (a coastal city in Southeast China, with a incidence of 21/100,000) (Zheng and Zhang, 2007). The incidence of papillary thyroid carcinoma, which is the most common histologic type of thyroid malignancy, is increasing worldwide (Davies and Welch, 2006). Recently, widespread use of ultrasonography (US) and US-guided fine needle aspiration biopsy (FNAB) has facilitated the diagnosis of papillary thyroid microcarcinoma (PTMC), which is defined by the World Health Organization as a papillary carcinoma measured at 10 mm or less in its maximal diameter (Davies and Welch, 2006). However, the management of PTMC remains controversial. Although some clinicians believe that observation is appropriate,