Primordial odontogenic tumour: A systematic review of the common but also unusual features of this novel entity

New diagnostic molecular markers and biomarkers in odontogenic tumors

Odontogenic tumors comprised of complex heterogeneous lesions that diverse from harmatomas to malignant tumors with different behavior and histology. The etiology of odontogenic tumors is not exactly determined and pathologists deal with challenges in diagnosis of odontogenic tumors because they are rare and obtained experiences are difficult to evaluate. In this study, we describe immunohistochemical and molecular markers in diagnosis of odontogenic tumors besides advanced diagnostic technique. Immunohistochemical features of odontogenic tumors beside the clinical features and radiological finding can help us to determine the correct diagnosis. Although these markers are neither specific nor sensitive enough, but analysis of gene expression provides definitive confirmation of diagnosis. In addition, "-omics" technology detected specific molecular alternation associated with etiology such as genomics, epigenomics, transcriptomics, proteomics and metabolomics. The post transcriptional events such as DNA methylation and chromatin remodeling by histone modification affect the changes in epigenome. Furthermore, non-coding RNAs like micro-RNAs, long noncoding RNA (lncRNA) and small non-coding RNA (snoRNA) play regulatory role and impact odontogenesis. Molecular marker propose their potential role in etiopathogenesis of odontogenic tumors and suitable candidate in diagnostic, prognostic and therapeutic approaches in addition to patient management. For future evaluations, organoid represents in vitro tumor model-study for tumor behavior, metastasis and invasion, drug screening, immunotherapy, clinical trial, hallmarks association with prognosis and evolution of personalized anti-cancer therapy. Moreover, organoid biobank help us to check genetic profile. We think more investigation and studies are needed to gain these knowledges that can shift therapeutic approaches to target therapy.