Re-evaluation of common paradigms regarding the clinical appearance of oral mucosal malignancies

Purpose: To evaluate the clinical appearance and rate of ulceration of oral mucosal malignancies, and to investigate the accuracy of clinical provisional diagnoses. Methods: A 10-year retrospective analysis, which included diagnostic biopsies of malignant tumors of the oral mucosa. The clinical provisional diagnoses were compared with final diagnoses. Results: Two hundred and twenty-seven oral mucosal malignant tumors were included. Squamous cell carcinoma and its variants accounted for the majority (78%) of all malignant tumors. The most common clinical presentations were non-ulcerated (59.7%) and ulcerated masses (20.4%). Only 11.9% presented as indurate ulcers. The highest ulceration rate of all malignancies was recorded for SCC, with only about half of SCC and its variants ulcerated at the time of biopsy. 31.1% of all malignancies were not clinically suspected to be malignant and did not even include a request to rule out malignancy. There was a better agreement between the clinical provisional diagnoses and microscopic diagnoses in the SCC group than in other types of malignancy (P < 0.001). Conclusion: Within this study sample, non-ulcerated masses rather than indurate ulcers are the most common clinical appearance of oral mucosal malignancies, and even for SCC, that showed the highest ulceration rate at presentation, half were non-ulcerated. Approximately, one-third of oral mucosal malignancies were not suspected to be malignant prior to biopsy. Thus, the level of suspicion currently reserved for mucosal ulcers and ulcerated masses should also be applied to non-ulcerated oral mucosal masses.