Mini-Symposium: Oral and Maxillofacial PathologyPapillary and verrucous lesions of the oral mucosa

A wide variety of papillary and verrucous lesions can affect the oral mucosa. Benign and reactive lesions (e.g. squamous papilloma, verruciform xanthoma) usually present little diagnostic difficulty. However, premalignant and malignant verrucous and papillary lesions pose a much greater diagnostic challenge, not helped by often confusing terminology. For example, papillary hyperplasia is a reactive inflammatory condition, whereas the term “verrucous hyperplasia” is often used to describe a potentially malignant lesion, which is probably part of the spectrum of verrucous carcinoma. A classical verrucous carcinoma, with an exo-/endophytic growth pattern and a “pushing” invasive front is easily identified, but many exophytic verrucous proliferations can also show endophytic growth. These can reasonably also be considered as verrucous carcinoma and managed accordingly. The distinction becomes academic in the face of conventional invasion, when squamous cell carcinoma is the appropriate diagnosis. This review aims to summarise and highlight the key features seen in these lesions, and to provide a practical approach for tackling these entities in routine diagnostic practice.