Pathology · single question
A lesion on the floor of the mouth appears thick, white, corrugated, and 'spongy' rather than ulcerated or indurated. What is the most likely diagnosis?
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Correct answer: B. White sponge nevus (a benign, autosomal dominant condition causing thick, corrugated, white oral mucosa, often bilateral and present since childhood)
White sponge nevus is a benign, hereditary (autosomal dominant) condition caused by mutations in keratin genes, presenting as a thick, white, corrugated, spongy-appearing mucosal lesion, often bilateral and symmetric, typically noted since childhood/adolescence, and requiring no treatment. Squamous cell carcinoma, by contrast, classically presents as an ulcerated, indurated lesion with irregular borders — a very different clinical picture from the 'spongy, non-ulcerated' description here.