Читать книгу Anterior Skull Base Tumors - Группа авторов - Страница 39

Inverted papilloma is characterised by an inward growth of squamous papilloma with transitional epithelial structures. This lesion is more common in males than females and has a propensity for recurrence and malignant progression. The detection of dysplasia and/or squamous differentiation (keratinisation) is a feature considered to predict malignant transformation. Grossly, inverted papillomas are typically tan to grey polypoid soft tissue masses with a mulberry appearance. These lesions occur in an older age group. Keratinisation may be present in some lesions and this feature may indicate potential progression. A characteristic feature of this lesion is the presence of intraepithelial microcysts with macrophages, cellular debris, and mucin-like materials. Malignant transformation has been reported to occur in 10% of these lesions. Therefore, identification of dysplasia and carcinoma in situ is critical to predict the malignant progression of these lesions. Low HPV subtypes have been identified in inverted papillomas by in situ hybridisations and polymerase chain reactions. No clear association between HPV status and malignant transformation has been established [44–47].

Table 4. Genetic rearrangements of potential clinical significance in skull base malignancies