Squamous Cell Carcinoma in situ Features

• A: Epidermal Thickening

• B: DEJ Alteration

• C: Hyperkeratotic Layering

• In most early SCCIS epidermal thickening is mainly focused to the Stratum Spinosum layer

• Thickening of the Stratum Corneum layer can also be present

• Increased prominence and thickness of the DEJ is typical for SCCIS

• Increased DEJ thickness and increased hyporeflectivity of thickened Stratum Spinosum region linked to increased dysplastic cell content

• Hyperreflective areas can sometimes be observed at the interface between the Stratum Corneum and Spinosum layers representing increased keratin deposition

• Increased hyporeflectivity of the DEJ can in some cases make identifying the deep margin difficult, however there is always a textural change between the epidermal keratinocytes and the underlying collagen and adnexal structures.