Dentigerous Cysts and Ameloblastomas; Expression of Mcm2 in Dentigerous Cysts and Ameloblastomas an Immunohistochemical Study

.. Objectives: The aim of study was to observe the expression of MCM2 in dentigerous cyst and ameloblastoma. Introduction: Minichromosome maintenance protein (MCM2) may be a structurally and functionally complicated replication moiety that synergizes with different molecular factors therefore regulate DNA synthesis. MCM proteins play a job in maintaining genomic integrity and stop re-replication once per cell cycle. It’s absent from chromatin in quiescent cells however abundant in mitotically active cells so making it a helpful marker for cellular proliferation. Dentigerous cyst (DC) is the commonest biological process odontogenic cyst having high proliferative index that may lead to dysplastic changes and development of tumours. Ameloblastoma is uncommon, benign and regionally aggressive odontogenic neoplasm with high rate of repetition after surgery. Study design: It was a descriptive study and designed to work out the expression of MCM2 in DCs and ameloblastomas. Setting: Department of Morbid Anatomy and Histopathology/ Oral Pathology. Period: Six months. Material and methods: Twenty-five patients presenting with DCs (n=12) and ameloblastomas (n=13) were selected. Clinical and radiographical findings were recorded and biopsies were submitted for histological diagnosis. MCM2 immunopositivity was assessed by immunohistochemistry in four microscopic high power fields showing most range of immunopositive cells. Results: Mean age was 26.5± 11.24 years and 42.07± 9.24 years whereas male to feminine magnitude relation was 7:5 and 7:6 for DCs and ameloblastomas severally. Most of the patients (58.3%) of DCs were asymptomatic whereas 41.6% patients reportable with painful swelling. Comparing, all patients with ameloblastomas conferred with painless swelling. Radiographically, all DCs were unicystic radiolucent lesions. While 46.2% of ameloblastomas were unicystic whereas 53.8% were multicystic radiolucent lesions. Histologically, basal layer atypia was seen in 50% and 23% of DCs and ameloblastomas respectively. High MCM2 immunoreactivity was ascertained within the epithelial lining of the DCs and the neoplastic cells of ameloblastomas. Conclusion: MCM2 expresses the higher proliferation index that might lead to neoplastic development in DCs while local invasive and recurrence potential in ameloblastomas.