Potential significance ofpodoplanin immunohistochemical expression in papillary thyroid carcinoma.

Abstract

Podoplanin (PDPN) is alymphatic endothelial marker expressed by arange ofhuman malignancies in which it has been shown to contribute to tumor progression and metastasis. However, there is alack ofthestudies, examining thefunction ofPDPN in thyroid cancer. Thecurrent study was performed to explore the possible diagnostic value ofPDPN expression in papillary thyroid cancer (PTC) and to evaluate themarker's potential for prediction ofregional lymph node metastasis. Lymphatic vascular density (LVD) and thestromal/cancer-associated fibroblasts (CAFs), labeled by PDPN, were examined in PTC compared to theother thyroid lesions. Thecurrent study included 50 cases ofPTC and 50 cases ofnon-PTC thyroid lesions. Immunohistochemical staining was performed using monoclonal PDPN antibodies. Podoplanin expression was scored as positive and negative. Podoplanin expression was found in 36% ofPTC cases, but it was not found in benign, low risk (borderline), or malignant lesions other than PTC. Furthermore, lymph node metastasis was significantly correlated with PDPN expression, LVD and CAFs (p-values<0.00001,<0.001 and 0.0002 respectively). These findings support thediagnostic utility ofPDPN expression in PTC and its predictive value for LN metastasis.