Journal of Cytology

ORIGINAL ARTICLE
Year
: 2020  |  Volume : 37  |  Issue : 4  |  Page : 174--181

Molecular testing for BRAFV600E and RAS mutations from cytoscrapes of thyroid fine needle aspirates: A single-center pilot study


Ojas Gupta1, Upasana Gautam1, Muralidaran Chandrasekhar1, Arvind Rajwanshi1, Bishan Dass Radotra2, Roshan Verma3, Radhika Srinivasan1 
1 Department of Cytology and Gynecological Pathology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
2 Department of Histopathology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
3 Department of Otorhinolaryngology, Postgraduate Institute of Medical Education and Research, Chandigarh, India

Correspondence Address:
Dr. Radhika Srinivasan
Professor and Head, Department of Cytology and Gynecological Pathology, Postgraduate Institute of Medical Education and Research, Chandigarh - 160012
India

Context and Aim: Molecular testing of thyroid FNA has been advocated in the indeterminate categories of The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) 2018. The utility of cytoscrapes of thyroid FNA samples for BRAF V600E and RAS mutations was evaluated in this pilot study. Methods and Materials: Thyroid FNA samples between 2015 and 2018 from TBSRTC categories 3–6 were included. DNA was extracted from one to two representative smears (cytoscrape). Real-time PCR for BRAF V600E and RAS(KRAS, NRAS, and HRAS) gene mutations was performed. Histopathology correlation was available in 44 cases. Statistical Methods: Chi-square test and calculation of sensitivity, specificity, and positive/negative predictive values were performed. Results: A total of 73 thyroid FNA cases and 11 nodal metastases of papillary thyroid carcinoma (PTC) were evaluated. The DNA yield ranged from 1.9 to 666 ng/μl (mean 128 ng/μl) in 80 cases and was insufficient in four cases. Overall, mutations were seen in 45 (56.25%) cases with BRAF V600E, NRAS, HRAS, and KRAS in 21 (46.7%), 19 (42.2%), 4, and 1 cases, respectively. BRAF V600E mutation was seen in PTC (11/18, 61%), nodal PTC metastases (5/10, 50%), and occasionally in TBSRTC category 3 (1/18, 5.5%). NRAS mutations were seen across all categories and were maximum in the AUS/FLUS group (6/18, 33%). BRAF V600E /RAS testing had an overall sensitivity, specificity, and positive and negative predictive values of 61.7%, 80%, 91.3%, and 38%, respectively, for the detection of malignancy. In indeterminate thyroid nodules, the sensitivity, specificity, PPV, and NPV were 56.2%, 80%, 81.8%, and 53.3%, respectively. Conclusion:BRAF V600E/RAS mutation testing from cytoscrapes are useful as a rule-in test for indeterminate thyroid nodules and provide molecular confirmation in nodal metastases of PTC.


How to cite this article:
Gupta O, Gautam U, Chandrasekhar M, Rajwanshi A, Radotra BD, Verma R, Srinivasan R. Molecular testing for BRAFV600E and RAS mutations from cytoscrapes of thyroid fine needle aspirates: A single-center pilot study.J Cytol 2020;37:174-181


How to cite this URL:
Gupta O, Gautam U, Chandrasekhar M, Rajwanshi A, Radotra BD, Verma R, Srinivasan R. Molecular testing for BRAFV600E and RAS mutations from cytoscrapes of thyroid fine needle aspirates: A single-center pilot study. J Cytol [serial online] 2020 [cited 2021 Apr 23 ];37:174-181
Available from: https://www.jcytol.org/article.asp?issn=0970-9371;year=2020;volume=37;issue=4;spage=174;epage=181;aulast=Gupta;type=0