Histologic subtype of oral squamous cell carcinoma with a focus on carcinoma cuniculatum

Abstract

Squamous cell carcinoma, which accounts for more than 90% of all malignant lesions in the oral cavity.　Although most cases are well-differentiated showing invasive growth forming nests with keratinization, there are rare histologic subtypes of squamous cell carcinoma that have unique histologic features.　Among these, carcinoma cuniculatum has been increasingly reported recently.　Although it shows marked endophytic growth, its prognosis seems to be better than conventional oral squamous cell carcinoma.