Keratinocytic tumours form a wide continuum from benign tumours to malignant tumours. This spectrum includes:
- benign adnexal tumours, often showing follicular differentiation
- tumours of intermediate malignant potential, such as keratoacanthoma (which usually resolve)
- pre-invasive lesions, such as Bowen’s diseasecSCC in situ (also known as intra-epidermal SCC) (cutaneous squamous cell carcinoma in situ) and actinic keratosis
- frankly malignant tumours, such as basal cell carcinoma and cutaneous squamous cell carcinoma
- rare tumours, such as Merkel cell carcinoma, Paget’s disease and atypical fibroxanthoma.
Topics covered in this section include: