Clinicopathological features of two cases of rearranged papillary thyroid carcinoma: a case report.

Rearrangements involving the neurotrophic-tropomyosin receptor kinase (NTRK) gene family (, and ) have been identified as drivers in a wide variety of human cancers. However, the association between rearranged thyroid carcinoma and clinicopathological characteristics has not yet been established. In our study, we retrospectively reviewed medical records of thyroid cancer patients and identified 2 cases with rearrangement, no additional molecular alterations were observed in either of these cases. The fusion of the rearrangement in both cases was (E4)::(E14). By analyzing the clinicopathological features of these two cases, we found that both were characterized by multiple tumor nodules, invasive growth, and central lymph node metastases, indicating the follicular subtype of papillary thyroid carcinoma. Immunohistochemical staining profiles showed CD56-, CK19+, Galectin-3+, HBME1+. These clinicopathological features suggest the possibility of rearranged thyroid carcinoma and highlight the importance of performing gene fusion testing by FISH or NGS for these patients.