Impact of CD34-dependent Micro Vessel Density on Periapical Odontogenic Cysts

Odontogenic cysts belong to a type of lesions with endodontic origin that in some cases mimic even aggressive odontogenic tumors sharing with them similar radiographic features. Periapical cysts (PCs) belong to the inflammatory odontogenic cysts sub-category and rarely squamous cell carcinoma arises from their hyperplastic/ dysplastic epithelia. This study aimed to explore the impact of cluster differentiation 34 (CD34) protein expression combined with micro vessel density (MVD) on PCs.

Forty-eight (n=48) archival, formalin-fixed, and paraffin-embedded PC tissue specimens were included in the study. Immunohistochemistry (IHC) was performed in the corresponding tissue sections using an anti- CD34 antibody. CD34 expression levels and also MVD in the examined cases were measured by implementing a digital image analysis protocol.

CD34 over-expression (moderate to high staining intensity levels) were detected in 29/48 (60.4%) cases, whereas the rest of them (19/48-39.6%) were characterized by low levels of expression. Extended MVD was identified in 26/48 (50.1%) cases correlated with CD34 over-expression, epithelial hyperplasia (p-value=0.001), and marginally with inflammatory infiltration level in the examined lesions (p-value=0.056).

CD34 over-expression combined with increased MVD is associated with a neoplastic-like (hyperplastic) phenotype in PCs as a result of increased neo-angiogenic activity. These histopathological characteristics rarely form an eligible substrate for squamous cell carcinoma onset in untended cases.