Clinical Variability in Oral Squamous Cell Carcinoma: A Retrospective Analysis Proposing a Practical Morphological Classification

OBJECTIVE: To propose a clinical classification system for oral squamous cell carcinoma (OSCC) based on lesion characteristics, aiming to enhance early recognition and initial clinical diagnostic hypothesis rate in clinical practice. METHODS: A retrospective analysis of 422 OSCC cases was conducted from 2005 to 2023. Lesions were clinically categorized through clinical photographs as either "conventional" (including non-ulcerated plaques; red, white, or mixed and ulcerated infiltrative lesions with raised indurated margins) or "atypical" (different from the one described above) based on their presentation. Atypical cases were further subclassified into morphological types. RESULTS: Of the 422 OSCC cases, 316 (74.9%) were classified as conventional and 106 (25.1%) as atypical. Conventional cases were predominantly ulcerative or leukoplakic, while atypical cases exhibited fissure-like and exophytic patterns. Tongue border was most commonly affected in conventional OSCC, while floor of the mouth and buccal mucosa predominated in atypical forms. CONCLUSION: Approximately one-quarter of OSCC cases present with atypical clinical features. The proposed classification provides a practical tool for clinicians to recognize these variants. However, further prospective validation is warranted to determine whether its application improves clinical recognition and diagnostic accuracy.