squamous cell ca

Question 1

definition of squamous cell carcinoma

Answer 1

malignancy of the epidermal keratinocytes of the skin

Marjolin’s ulcer is a SCC that arises in an area of chronically inflammed/scarred skin

Question 2

aetiology of SCC

Answer 2

main RF is UV from sunlight exposure

actinic keratoses (sun-induced precancerous lesions)

radiation

carcinogens - tar derivatives, cigarette smoke, soot, industrial oils, arsenic

chronic skin disease (eg lupus, leukoplakia)

HPV

long term immunosuppression - transplant, HIV

DNA repair defects - xeroderma pigmentosum

Question 3

epidemiology of SCC

Answer 3

second most common cutaneous malignancy (20% of skin cancers)

often occuring in middle ages and elderly light skinned individuals

annual incidence is 1/4000

men more

Question 4

sx of SCC

Answer 4

skin lesion

ulcerated

recurrent bleeding or non-healing

Question 5

signs of SCC

Answer 5

variable appearance

ulcerated

hard, raised edges

hyperkeratotic

crusted or scaly

non-healing lesion

often in sun-exposed areas

palpate for focal lymphadenopathy

. May begin in solar keratoses or be found on the lips of smokers or in long-standing ulcers (=Marjolin’s ulcer)

Question 6

pathology of SCC

Answer 6

Bowen’s disease is intra-epidermal ca in situ (intra-epidermal proliferation of atypical keratinocytes, bm is intact)

seen as soiltary or multiple red-browwn scaly patches

in SCC malignant keratinocytes invade locally into the dermis and can spread to local LN and distally met eg lungs and liver

staging TNM

Question 7

Ix for SCC

Answer 7

skin biopsy - confirms malignancy, distinguish from other skin lesions

FNAC or LN biopsy - only necessary if suspect met

staging - CT and/or MRI, PET