Well-differentiated Thyroid Cancer With a Minor Poorly Differentiated Component

Well-differentiated carcinoma (WDC) accounts for up to 90% of all thyroid cancers. The presence of a minor poorly differentiated (PD) component (mainly insular pattern) might represent an additional critical parameter for patients' prognosis and outcome. The role of both CXCR4 (a chemokine inducing cytoskeletal rearrangement and cell adhesion) and BRAF mutation have been studied in WDC (mainly papillary thyroid cancer and its variants), highlighting their critical role in tumor progression, local infiltration, and metastases. We discussed the clonal heterogeneity through the prognostic role of CXCR4 and BRAF mutation in WDC with a minor PD/insular component. Of our 16 WDC cases with a PD/insular component, up to 40% underwent surgery. The cases were subclassified according to the PD percentage as (1)