Peritumoral bone changes in mandibular gingival squamous cell carcinoma: A prospective radiologic-histopathologic correlation study

Abstract

Background/purpose: Accurate differentiation between tumor invasion and reactive bone response is essential for surgical planning in squamous cell carcinoma (SCC). This prospective study investigated the radiologic-histopathologic correlation of peritumoral bone changes to distinguish malignant invasion from reactive alterations. Materials and methods: Twenty-four patients with SCC involving the mandibular gingiva or retromolar trigone underwent contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI), followed by mandibulectomy. Peritumoral bone was radiologically classified as intact, altered, or infiltrated. Resected specimens underwent cone-beam CT and histopathologic evaluation. Histopathologic classification included: (1) pattern of invasive tumor front (erosive or infiltrative), and (2) type of peritumoral bone change (sclerosis-dominant, fibrosis-dominant, or invasion-dominant). Radiologic and histopathologic findings were correlated, and five-year recurrence and survival rates were analyzed according to histopathologic classifications. Results: Seventeen of 24 patients exhibited intact or altered peritumoral bone on imaging, which corresponded to sclerosis- or fibrosis-dominant types on histopathology. All infiltrated peritumoral bone cases were histopathologically confirmed as invasion-dominant type, indicating tumor invasion. Patients with sclerosis- or fibrosis-dominant types had significantly better five-year overall survival than those with the invasion-dominant type (P = 0.04), although recurrence rates did not significantly differ. Additionally, an infiltrative pattern of invasive tumor front was associated with higher recurrence and mortality compared to an erosive pattern (P = 0.02). Conclusion: Most peritumoral bone changes observed on CT and MRI in mandibular gingival SCC were found to be reactive rather than truly invasive on histopathologic evaluation. Differentiating these changes has prognostic value and helps identify patients with poorer survival. © 2025 Association for Dental Sciences of the Republic of China