Immunohistochemical Expression of VEGF, CD34, and Ki-67 in Odontogenic Tumors and Their Correlation with Biological Behavior: Evidence from Northern Nigerian Institutions

Odontogenic tumors display a wide spectrum of biological behavior ranging from indolent and self-limiting to locally aggressive and rarely malignant. Conventional histopathological classification alone may be insufficient to predict recurrence risk and guide the extent of surgical intervention. Immunohistochemical (IHC) markers of angiogenesis (VEGF, CD34) and cellular proliferation (Ki-67) have been proposed as surrogate indicators of biological aggressiveness in soft tissue and bony tumors, but systematic IHC studies in odontogenic tumors from the Northern Nigerian population are absent. This original PhD study evaluates the IHC expression of VEGF, CD34 (microvessel density), and Ki-67 (proliferation index) in a series of 150 odontogenic tumors archived in pathology departments of ABUTH Zaria, UDUTH Sokoto, ATBUTH Bauchi, and JUTH Jos, representing the North West, North Central, and North East zones. Tumors evaluated include ameloblastoma, adenomatoid odontogenic tumor, odontogenic myxoma, calcifying epithelial odontogenic tumor, and odontogenic keratocyst. Quantification of IHC expression was performed using digital image analysis. Results reveal significantly higher Ki-67 proliferation indices in ameloblastoma compared to non-aggressive odontogenic tumors, with plexiform ameloblastoma demonstrating the highest VEGF expression. CD34 microvessel density was positively correlated with Ki-67 expression, suggesting angiogenesis-proliferation coupling in aggressive subtypes. VEGF and Ki-67 co-expression predicted recurrence at five-year follow-up with 74.3% sensitivity. The study advances the molecular profiling of odontogenic tumors in northern Nigeria and proposes an IHC-based aggressiveness index to supplement histological grading. Keywords: odontogenic tumors, VEGF, Ki-67, immunohistochemistry, northern Nigeria.