Squamous cell carcinoma and precursors Flashcards
What is squamous cell carcinoma?
A malignancy of the supra-basal keratinocytes of the epidermis
Where do squamous cell carcinomas most commonly occur?
On sun exposed sites (Face, ears, dorsal hands) in the elderly
What are some rarer locations of SCC formation?
Chronic leg ulcers (E.g. stasis ulcers)
Sites of burns
Sinuses
Areas affected by chronic lupus vulgaris
What are some conditions associated with SCC?
Xeroderma pigmentosum
Dystrophic variant epidermolysis bullosa
What is the spectrum of disease leading to SCC?
Actinic keratosis (Mildest)
Bowen’s disease
Squamous Cell Carcinoma
What is actinic keratosis?
A partial thickness, keratinocyte dysplasia of the epidermis
What is Bowen’s disease?
A full thickness, keratinocyte dysplasia of the epidermis
Where do actinic keratoses most commonly form?
Sun-exposed areas (Scalp, face, hands)
Describe the histology of actinic keratosis
Presence of parakeratin (Nucleated cells) in the keratin layer shows fast turnover
Where does Bowen’s disease most commonly form?
Lower leg
Females
How will Bowen’s disease present on the skin?
Scaly plaque or patch with an irregular border
How will Bowen’s disease show on histology?
What condition is shown?
Actinic keratosis
What condition is shown?
Bowen’s disease
What is a viral SCC precursor?
Penile Bowen’s disease (Erythroplasia of Queryat)
What virus can cause penile Bowen’s disease?
HPV type 16
How will SCC present?
Fast growing (2-3 months) often tender scaly or ulcerated lesion
What condition is shown?
Actinic keratosis
What condition is shown?
Bowen’s disease
What condition is shown?
Squamous cell carcinoma
What condition is shown?
SCC - Common on bald scalps due to sun damage, plus previous excision scar on the left, so highly suggestive of SCC
What condition is shown?
SCC - Ears and lips are common sites of sun damage due to forgetting to apply sun cream there, also increased risk of metastases
What condition is shown?
SCC on leg ulcer
What are some non-surgical treatments for SCC?
liquid nitrogen or cytotoxic cream (Efudix) can be used in superficial, non-life threatening lesions
What are some adverse prognostic features of SCC?
- Thickness > 4mm and poor differentiation
- lymphatic / vascular space invasion
- perineural spread
- specific sites poorer prognosis - scalp, ear, nose
How is SCC usually managed?
Surgical excision with a wide margin
