Different CXCR4 expression according to various histologic subtype of papillary thyroid carcinoma. 
Functional chemokine (C-X-C motif) receptor 4 (CXCR4) is well known to be over-expressed in papillary thyroid carcinoma (PTC).  The aim of this study was to evaluate whether or not the expression of CXCR4 is different by histological subtypes of PTC and to elucidate the relationship between the expression of CXCR4 and clinicopathologic factors.  CXCR4 expression in 127 PTC samples was assessed using immunohistochemical staining.  The expression of CXCR4 showed different patterns according to the histological subtype of PTC (p < 0.001).  A strong expression of CXCR4 was observed more frequently in the poorly differentiated region of PTC (81.0 %) than in classical PTC (50.0 %).  Strong CXCR4 expression was less frequently shown in follicular variant (33.9 %) and in diffuse sclerosing variant (14.3 %) of PTC.  CXCR4 expression showed a distinct pattern according to the histological subtype of PTC although not associated with other clinicopathological parameters.