Cutaneous squamous cell carcinomas are associated with basal proliferating actinic keratoses.

Basal proliferative AKs, as well as atypical keratinocytes restricted to the lower third of the epidermis, are most commonly seen adjacent to iSCC, with less evidence for full-thickness epidermal dysplasia. Our study supports the important role of dysplastic keratinocytes in the epidermal basal layer and their potential association with iSCC.