Cytologic, histologic and molecular findings of papillary thyroid carcinoma variants, one institution’s experience

Abstract

Papillary thyroid carcinoma (PTC) has two major types, classic (PTCC) and follicular variant (FVPTC), which correlate with molecular findings and have varying clinical implications. We assessed the cytologic findings and subsequent surgical pathology findings with the molecular mutations in these two groups, including microcarcinomas. Fourty-four patients with PTC resections over a one-year period were retrospectively examined in conjunction with previous cytologic diagnoses. BRAF, NRAS and TERT promoter mutations for the resected specimens were analyzed. Correlation with previous cytology in regard to molecular mutations and tumor size (microcarcinoma) were made. Significantly more BRAF V600E mutations were seen with PTCC, whereas significantly more NRAS mutations were seen with FVPTC. TERT mutations were only seen with PTCC. Molecular studies for thyroid carcninomas are becoming increasingly more common and influence treatment and patient prognosis. BRAF and or TERT mutations are associated with a worse prognosis. NRAS mutations associated with FVPTC and may lead to milder cytologic changes compared to the BRAF- and TERT-driven PTCC.