The BRAF^T1799AMutation is not Associated with Occult Contralateral Carcinoma in Patients with Unilateral Papillary Thyroid Microcarcinoma

Abstract

Background: The phenomenon of occult carcinoma maybe observed in patients with clinically unilateral papillary thyroid microcarcinoma (PTMC). Although many studies have reported that the BRAF T1799A mutation is associated with aggressive PTMC, the relationship between BRAF T1799A mutation and occult carcinoma is unclear. The aim of this study was to investigate the risk factors, including BRAF T1799A mutation, for occult contralateral carcinoma in clinically unilateral PTMC accompanied by benign nodules in the contralateral lobe. Materials and Methods: From January 2011 to December 2013,we prospectively enrolled 89 consecutive PTMC patients with clinically unilateral carcinoma accompanied by benign nodules in the contralateral lobe who received a total thyroidectomy and cervical lymph node dissection. BRAF T1799A mutation was tested by pyrosequencing on postoperative paraffin specimens. The frequency and predictive factors for occult contralateral carcinoma were analyzed with respect to the following variables: age, gender, family history, tumor size, presence of Hashimoto thyroiditis, extrathyroidal extension, central lymph node metastasis, multifocality of primary tumor, or BRAF T1799A mutation. Results: A total of 36 patients (40.4%) had occult PTMC in the contralateral lobe. The median diameter of the occult tumors was 0.33±0.21 cm. The BRAF T1799A mutation was found in 38 cases (42.7%). According to the univariate analysis, there were no significant differences between the presence of occult contralateral carcinoma and age, gender, family history, tumor size, presence of Hashimoto thyroiditis, extrathyroidal extension, central lymph node metastasis, multifocality of primary tumor, or BRAF T1799A mutation. Conclusions: Using current methods, it is difficult to preoperatively identify patients with PTMC, and further research is needed to determine predictive factors for the presence of occult contralateral carcinoma in patients with unilateral PTMC.

Risk Factors for Contralateral Occult Carcinoma in Patients With Unilateral Papillary Thyroid Carcinoma: A Retrospective Study and Meta-Analysis

“…Contralateral occult PTC is a specific subtype of bilateral multifocal PTC. It has been reported that the rate of occult PTC in the contralateral lobe ranges from 12% to 40% (11)(12)(13). For contralateral occult PTC, TL may be insufficient and could cause relapse and even lead to re-operation, which brings higher risks.…”

Bilateral papillary thyroid cancer: Pitfalls of ACR TI-RADS and evaluation of modified parameters

“…We also need to pay attention to occult cancer in clinical practice. It has been reported that the incidence of occult PTC in the contralateral lobe is 12% − 40% [32][33][34]. After adjustment with our method, the detection ability of occult carcinoma in the thyroid contralateral lobe was signi cantly improved (the missed diagnosis rate decreased from 21.1-4.5%), and this result was validated in the validation set (the missed diagnosis rate decreased from 11.4-2.9%).…”

Incidence and risk factors for occult lesions in low-risk papillary thyroid microcarcinoma patients with tumor characteristics appropriate for thermal ablation: A retrospective study

“…Among patients undergoing total thyroidectomy for preoperatively detected unilateral PTMC, 15.5% to 40.4% exhibit contralateral occult carcinoma. [28][29][30][31] Even with preoperative solitary PTMC consideration, 3.7% of patients develop ipsilateral occult carcinoma, and 15.5% to 22.3% contralateral occult carcinoma. [32,33] In this investigation, 11.0% (28/255) of patients had contralateral occult carcinoma.…”