A Comparative Immunohistochemical Study of Expression of Syndecan-1 (CD138) and Podoplanin in Keratocystic Odontogenic Tumor, Orthokeratinized Odontogenic Cyst and Dentigerous Cyst

Background: Odontogenic lesions can bring about diagnostic challenges due to overlapping histology among pathologists. Thus, there are few tumor markers that provide accurate diagnosis. Syndecan-1 (CD-138) and podoplanin (PDPN) are proteoglycans that have been described as substantial diagnostic and prognostic markers in various odontogenic lesions. Aim: This study aims to evaluate and compare the immunohistochemical expression of syndecan-1 (CD-138) and podoplanin in keratocystic odontogenic tumor, orthokeratinized odontogenic cyst (OOC), and dentigerous cyst (DC). Materials and Methods: The formalin-fixed paraffin-embedded tissue blocks of KCOT, OOC, and DCs were retrieved form the archives of department. Three sections each of 3 μm thickness were made using a rotary microtome and they were stained with syndecan-1 (CD-138) and podoplanin (PDPN) using immunohistochemical methods and standard hematoxylin and eosin stain. Results: Immunohistochemical expression of syndecan-1in KCOT was found to be weakly to moderately positive in 6 cases with 2 cases exhibiting positive expression. In OOC, 3 cases displayed negative expression-1 whereas 7 cases were weakly to moderately positive. Immunohistochemical expression of podoplanin in KCOT was observed to be weakly to moderately positive in 4 cases with 5 cases exhibiting strongly positive expression. In OOC, 3 cases displayed negative immunohistochemical expression for podoplanin and 4 cases were strongly positive. Immunoreactivity for podoplanin in DC was negative in 3 cases whereas 5 cases were weakly to moderately positive. Conclusion: The absence of significant correlation between expression of syndecan-1 and podoplanin reinforces the exact role of these proteins in the differentiation of odontogenic lesions which need to be elucidated further.