Histopathologic subtypes of squamoproliferative lesions include verruca (A) with papillomatosis, hyperkeratosis and hypogranulosis; actinic keratosis (not shown) with keratinocyte atypia without full thickness involvement or invasion; conventional (conv.) cutaneous squamous cell carcinoma (cSCC, B, atypical keratinocytes, inset E) with invasion of dermis; well differentiated keratoacanthomatous-type cSCC (cSCC-KA, F); and cSCC with wart-like features (cSCC-WF, C; atypical keratinocytes inset D). H&E stained sections, composite 4x orig. obj. mag. Insets (D, E) 20x orig. obj. mag.