Squamous Cell Carcinoma
SCC is a malignant tumour arising from the keratinising cells of the epidermis or its appendages. It can become invasive in it’s locality and has the potential to metastasis.
SCC usually presents as an indurated nodular keratinising or crusted tumour that may ulcerate, or it may present as an ulcer without evidence of keratinisation. They may bleed and they are often tender on examination. All patients where there is a possibility of a cutaneous SCC should be referred as an urgent suspected cancer.
Broadly there are two different types of SCC, well differentiated SCC (less aggressive) and moderately-poorly differentiated SCC (more aggressive).
These tend to grow slower with a keratotic surface in the early stages. Whilst the tumour grows the keratin production and cellular mass shifts towards cellular proliferation causing the surface to ulcerate and growth takes place predominantly at the margins with an increasing area of granulation tissue occupying the centre. The surface can shed, exposing an indurated ulcer. This ulcer can exude, bleed and be purulent, it may have a “punched out” margin. Whereas a BCC ulcer can be described as an ulcer where the edges are more rolled.
Moderate-poorly differentiated SCC
These have more disorganized keratin surfaces, often sparse and possibly absent. There can be overt ulceration with an undifferentiated (anaplastic) tumour, where the stratum corneum may have been eroded. More commonly seen on the lips and genitalia it can appear similar to granulation tissue. (12)