NCOA4 and carcinoma: PTCs positive for NCOA4/RET were significantly associated with larger tumor size (P = 0.021) and more frequently had extrathyroidal extension (P = 0.049), in contrast to carcinomas positive for other RET fusions, which were significantly associated with a predominant papillary growth pattern (P = 0.001) and CLT (P = 0.005).