Correlations between Molecular Landscape and Sonographic Image of Different Variants of Papillary Thyroid Carcinoma

Papillary thyroid carcinoma (PTC), the most common thyroid cancer, is predominantly driven by mutations in BRAF (primarily p. V600E) and RAS oncogenes. Ultrasound (US) examination provides significant diagnostic data in the management of thyroid nodules, as many sonographic features of thyroid lesions are correlated with the potential risk of thyroid carcinoma. The aim of the study was to analyze the current literature in regard to the potential associations between genetic landscape and sonographic features of PTC. Based on the current literature, sonographic features of PTCs correlate with their molecular drivers, particularly between tumors harboring BRAF versus activating RAS mutations, although many of these findings appear to be dependent on the tumor variant. Suspicious US findings, such as hypoechogenicity, spiculated/microlobulated margins, non-parallel orientation/taller-than-wide shape, and the presence of microcalcifications, are typical for PTC positive for BRAF mutations. On the contrary, tumors with RAS mutations are most frequently hypo- or isoechoic and ovoid-to-round in shape, with smooth margins and without calcifications. There are also some US features typical for PTCs harboring other mutations, including BRAF, RET/PTC rearrangements, PAX8-PPARγ, CTNNB1, and APC. However, further research is necessary, as some rare PTC variants still cannot be reliably analyzed due to the scarce published data.