[444] Application of BRAF V600E Mutation Detection to the Bethesda Thyroid FNA Classification System at an Academic Institution.

Constantine Theoharis, Pei Hui, David Chhieng, Adebowale Adeniran. Yale University School of Medicine, New Haven, CT

Background: Thyroid Fine Needle Aspiration is the standard preoperative diagnostic procedure in the evaluation of thyroid nodules but suffers limitations. BRAF V600E positivity is associated with worsened clinical prognosis including lymph node positivity. Our purpose was to correlate BRAF mutational status based on PCR-SSCP technique in Thyroid FNA with surgical outcome and regional nodal status.
Design: 82 patients, 72% female (average age: 51 years, range 17-96) underwent BRAF PCR-SSCP testing as an adjunct test to the Bethesda Thyroid FNA Classification System at our institution beginning 2/2010. The analytical sensitivity of BRAF was previously determined to be <5%, suitable for cytological specimens.
Results: Of the 82 patients, BRAF V600E mutation was detected in 37, the remaining 45 were wild type. Pre-operative BRAF/Cytologic evaluation is summarized in Table 1.

BRAF Findings v.s. Cytology in Thyroid FNA
 ThyroidFNA
Cytology DxBRAF (+)BRAF (-)
Positive327
Suspicious39
Follicular Neoplasm04
Atypical532


55 patients underwent thyroidectomy, 34 also included regional lymph nodal dissection. BRAF positivity was associated with surgically confirmed lymph node metastasis in 59% of cases. BRAF negativity was associated with surgically confirmed lymph node metastasis in 41% of cases. BRAF, as a predictor had: sensitivity 61%, specificity 50%, positive predictive value 50%, and negative predictive value 59%.
Conclusions: Patients with BRAF mutation as determined by PCR-SSCP mutation testing in cytological specimens is more likely to found to have papillary thyroid carcinoma on resection. In addition, BRAF mutation testing offers a similar detection frequency in predicting surgical lymph node positivity as reported in the literature. Therefore, the pre-operative utilization of BRAF testing using cytological FNA specimen may offer a highly desirable preoperative guidance in the surgical treatment of papillary thyroid carcinoma.
Category: Cytopathology

Wednesday, March 2, 2011 1:00 PM

Poster Session VI # 61, Wednesday Afternoon

 

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