A patient presents with a non-healing ulcer on the lateral tongue for over two weeks. What is the differential and recommended biopsy plan?

• A. Traumatic lesion
• B. Leukoplakia
• C. Lichen planus
• D. Traumatic lesion, leukoplakia, lichen planus, and squamous cell carcinoma with incisional biopsy recommended

Answer: (C)

Persistent non-healing ulcers on the tongue, especially on the lateral border, prompt clinicians to obtain a biopsy because cancer must be ruled out. Erosive lichen planus is a common mucosal disorder that can present as a painful, lasting ulcer in this area and may mimic squamous cell carcinoma. When you face such a lesion, the most informative step is an incisional biopsy that includes the ulcer edge and adjacent normal-appearing tissue, so the pathologist can assess both the epithelial changes and the subepithelial inflammatory pattern.

Why this fits best: trauma-related ulcers typically heal after removing the irritant, and leukoplakia usually appears as a white patch rather than a persistent ulcer. Squamous cell carcinoma must always be considered in a persistent tongue ulcer, but the clinical clue here—an ulcer pattern on the lateral tongue compatible with erosive lichen planus—makes lichen planus the leading consideration to confirm histologically. The definitive diagnosis comes from the biopsy, which will show the characteristic inflammatory and epithelial changes of lichen planus if present.