An immunohistochemical based assessment of murine double minute 2 (MDM2) and cyclin-dependent kinase 4 (CDK4) in jaw osteosarcoma and benign osseous lesions.

UNLABELLED: The diagnosis of primary bone tumours of the jaw often presents as a diagnostic dilemma. Overlap in clinical, radiological, and histological features between benign lesions like juvenile trabecular ossifying fibroma (JTOF); osteoblastoma (OB) and malignant tumours like low-grade osteosarcoma (LGOS) makes the diagnosis challenging. While osteosarcoma is a malignant tumour with poor prognosis requiring aggressive treatment, benign lesions have generally favourable outcome. This study aimed to assess the immunohistochemical expression of murine double minute 2 (MDM2) and Cyclin-dependent kinase 4 (CDK4) in low-grade osteosarcoma and benign osseous lesions.

METHODOLOGY: Immunohistochemical analysis was performed on tissue samples from diagnosed cases of LGOS, JTOF, and OB. The expression levels of MDM2 and CDK4 were analysed and compared across the three groups.

RESULTS: We found significantly higher expression of MDM2 and CDK4 in low-grade osteosarcoma compared to JTOF which showed negative expression in all of the cases. Osteoblastoma showed inconsistent and focal positivity contrary to OS where strong and diffuse expression of both the markers was observed. A strong co-expression of both the markers was also noted in 94% of OS cases.

CONCLUSION: Immunohistochemistry for MDM2 and CDK4 is a valuable diagnostic tool in differentiating low-grade osteosarcoma from benign mimics. This approach provides a cost-effective, reliable, and accurate means for diagnosing jaw bone tumours, particularly when tissue samples are insufficient or on small incisional biopsies where accurate diagnosis is of prime importance.