Evaluation of mirror image biopsy technique for the detection field change in patient with squamous cell carcinoma of oral tongue

Background: Squamous cell carcinoma (SCC) of the tongue is rising globally, particularly among individuals under 45, possibly due to genetic or unidentified etiological factors. In 2020, Iraq's prevalence (1.6/100,000) was lower than neighboring and industrialized countries. The mirror image biopsy technique, based on "field cancerization," involves biopsying the area opposite a confirmed lesion to identify hidden malignancies and guide treatment, especially in alcohol or tobacco users. Aim: To histopathologically evaluate mirror image biopsy findings in tongue SCC patients to detect abnormalities ranging from reactive changes to malignancy. Methods: A prospective study was conducted from January 2022 to December 2023 at the Maxillofacial Department, Al Shaheed Ghazi Al Harrery. Twenty tongue SCC patients (any age or gender) were included, excluding those with extensive, bilateral, or posterior tongue tumors or who declined the biopsy. Contralateral normal-appearing mucosa was biopsied under general anesthesia during primary tumor excision and analyzed histopathologically. Patients received post-operative care and follow-up. Results: Among 20 cases, 60% showed hyperplasia, and 40% dysplasia (mild: 5; moderate: 2; severe: 1). The mean age was 56.4 years, with no significant age or gender differences (P=0.852). Tumor grade (P=0.033) and size (P=0.016) significantly influenced results, while lymph node status (p=0.083) and tumor position did not. Conclusion: Dysplastic changes in mirror biopsies were significantly associated with higher tumor grades and larger sizes, highlighting the field cancerization concept. Comprehensive histopathological assessments are critical in managing tongue SCC.