Comprehensive clinicopathological evaluation of malignant localized gingival enlargements in the Thai population

Malignant localized gingival enlargements (LGEs) are rare and often clinically mimic reactive or benign lesions, creating diagnostic challenges. The present study aimed to evaluate the prevalence and origins of malignant LGEs, assess clinicopathological diagnostic concordance, and identify the distinction of clinical features in a Thai population. A total of 96 malignant LGEs diagnosed over a 40-year period were retrospectively analyzed. Demographic data, clinical characteristics, and clinical and pathological diagnoses were collected. Malignant LGEs were categorized by origin, and diagnostic concordance was evaluated. Clinical features were compared between epithelial and non-epithelial malignant LGEs, and a decision tree model was constructed to identify predictive factors. Epithelial (60.4%) and non-epithelial (39.6%) malignant LGEs indicated a comparable distribution. Non-epithelial lesions demonstrated substantially lower diagnostic concordance and were frequently misdiagnosed as reactive or benign conditions. Significant differences between groups were observed in age (P=0.004), surface texture (P=0.003), color (P=0.014), and location (P=0.044). Decision tree analysis identified age (P=0.018) and surface texture (P=0.03) as key predictors of non-epithelial malignant LGEs. Non-epithelial malignant LGEs are particularly prone to clinical misdiagnosis. Lesions occurring in younger patients, notably those with smooth surface texture, should raise suspicion for non-epithelial malignancy and prompt timely biopsy and referral. These findings may aid clinicians in improving early recognition of malignant LGEs.