Clinicopathological and Immunohistochemical Risk Predictors for Ameloblastoma Recurrence.

Area of Science:

• Oncology
• Oral and Maxillofacial Surgery
• Molecular Pathology

Background:

• Ameloblastoma (AMB) is a locally aggressive odontogenic tumor with a high recurrence rate.
• Understanding predictors of recurrence is crucial for effective management and improved patient outcomes.

Purpose of the Study:

• To investigate the association between clinicopathological and immunohistochemical variables and the recurrence of ameloblastoma.
• Specifically, to analyze the expression of human Mut-L homologue 1 (hMLH1) and human Mut-L homologue 2 (hMSH2) in recurrent and non-recurrent AMBs.

Main Methods:

• A retrospective, observational case-control study involving 44 AMB cases (22 recurrent, 22 non-recurrent) with over one year of follow-up.
• Quantitative immunohistochemical analysis of hMLH1 and hMSH2 nuclear expression.
• Statistical analysis included McNemar test, Kaplan-Meier survival analysis, and log-rank tests.

Main Results:

• Posterior mandible was the most common site for both recurrent and non-recurrent AMBs.
• Factors significantly associated with AMB recurrence included cortical bone expansion, absence of bone reconstruction, conservative treatment, loss of hMSH2 and hMLH1 immunoexpression, and strong Ki-67 immunoexpression.
• Significant risk factors for recurrence included anatomical location, locularity, cortical expansion, cortical perforation, bone resorption, tooth impaction, jaw reconstruction, and reduced immunoexpression of hMSH2 and hMLH1.

Conclusions:

• Radiographic appearance, treatment modality, and the immunoexpression of mismatch repair proteins (hMLH1 and hMSH2) are significant predictors of AMB recurrence.
• These findings can aid in identifying high-risk cases and tailoring treatment strategies to minimize recurrence.