The patient in this vignette most likely has oral leukoplakia, which is an example of squamous hyperplasia.
Oral leukoplakia is a lesion that is associated with an increased risk of oral squamous cell cancer, though not all leukoplakia-appearing lesions are pre-neoplastic. It is most commonly seen at the vermilion border of lower lip but can be seen anywhere in the mouth. Leukoplakia can be caused by alcohol and tobacco use (as in this patient), infection (EBV), and chronic irritation (e.g. poor-fitting dentures). Of note, these lesions cannot be scrapped off with gentle scrapping.
Reamy et al. discuss oral hairy leukoplakia which they note can be a marker for underlying immunodeficiency. They report that it is caused by the Epstein-Barr virus and may be treated with oral antivirals. As these lesions are pre-neoplastic, they can require biopsy to differentiate benign lesions from premalignant leukoplakia or squamous cell carcinoma.
Kumar et al. discuss the management of oral leukoplakia. They reported a rate of malignant transformation to range from 0.13 to 17.5%, with a gold standard diagnosis being histopathological examination of suspicious tissue. Associated factors for malignant transformation include age, type of lesion, site and size, dysplasia, and DNA content, but no single reliable biomarker has been shown to be predictive. Non-surgical management with pharmacologic therapy has not been shown to be effective prevention of malignant transformation and recurrence.
Figure A displays an example of tongue leukoplakia.
Answer 1: Fungal infections of the mouth, most commonly Candidasis, can cause white patches in the mouth but would be unlikely to cause such a focal lesion and would more commonly cause patches throughout the mouth.
Answer 3: Leukoplakia is a risk factor for cancer but is not yet by definition neoplastic.
Answer 4: Leukoplakia is not an example of metaplasia.
Answer 5: This lesion is most likely not caused by trauma to the oral mucosa.
Reamy BV, Derby R, Bunt CW. Common tongue conditions in primary care. Am Fam Physician. 2010 Mar 1;81(5):627-34.
PMID:20187599 (Link to Abstract)
Kumar A, Cascarini L, McCaul JA, Kerawala CJ, Coombes D, Godden D, Brennan PA. How should we manage oral leukoplakia? Br J Oral Maxillofac Surg. 2013 Jul;51(5):377-83.
PMID:23159193 (Link to Abstract)