The role of BRAFV600E mutation and ultrasonography for the surgical management of a thyroid nodule suspicious for papillary thyroid carcinoma on cytology.
BACKGROUND
This study was designed to investigate the role of BRAFV600E mutation status in cytology specimens and ultrasonography (US) when planning surgery for thyroid nodules with cytologic results suspicious for papillary thyroid carcinoma (PTC).


METHODS
From July 2008 to November 2008, 91 consecutive patients with cytologic results of suspicious for PTC underwent thyroidectomy. Before surgery, all patients received US-guided fine needle aspiration biopsy (US-FNAB) solely for the purpose of BRAFV600E mutation analysis of thyroid nodules suspicious for PTC on cytology. BRAFV600E mutations were tested by direct sequencing. We investigated the role of BRAFV600E mutation and US in planning the thyroid surgery.


RESULTS
Of 91 nodules suspicious for PTC, 42 (46.2%) were positive for the BRAFV600E mutation and confirmed to be PTC by histopathology. The positive predictive values of BRAFV600E mutation was 100%. Of the 49 nodules without the BRAFV600E mutation, 42 (85.7%) proved to be PTC. Thirty-nine of 42 (92.9%) PTCs were suspicious for malignant features on US. Two of seven (28.6%) benign lesions showed probably benign features. The sensitivity, positive predictive value, and accuracy of US in thyroid nodules without BRAFV600E mutations was 92.9% (39/42), 88.6% (39/44), and 83.7% (41/49), respectively.


CONCLUSIONS
The BRAFV600E mutation is a useful molecular marker for preoperative diagnosis of PTC and an indicator for therapeutic thyroid surgery in the nodule with cytologic results suspicious for PTC. In thyroid nodules without the BRAFV600E mutation, suspicious malignant features on US may help in planning the extent of thyroid surgery.
Moon
Hee Jung
HJ
Department of Radiology, Research Institute of Radiological Science, Yonsei University College of Medicine, Seoul, South Korea.
Kwak
Jin Young
JY
Kim
Eun-Kyung
EK
Choi
Jong Rak
JR
Hong
Soon Won
SW
Kim
Min Jung
MJ
Son
Eun Ju
EJ
D000328:Adult; D000368:Aged; D002291:Carcinoma, Papillary / Q000000981:diagnostic imaging / Q000235:genetics / Q000601:surgery; D017931:DNA Primers / Q000737:chemistry; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation / Q000235:genetics*; D009367:Neoplasm Staging; D011379:Prognosis; D011446:Prospective Studies; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics*; D012189:Retrospective Studies; D015996:Survival Rate; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging* / Q000235:genetics* / Q000601:surgery; D016606:Thyroid Nodule / Q000000981:diagnostic imaging* / Q000235:genetics* / Q000601:surgery; D014463:Ultrasonography
D017931:DNA Primers; C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf