Squamous cell carcinoma

Question 1

Define

Answer 1

Malignancy of the epidermal keratinocytes of the skin

Question 2

What is the cause for squamous cell carcinoma?

Answer 2

Keratinocyte derived skin cancers are mainly caused by UV light exposure.

• UV radiation induces direct abnormalities in keratinocytes’ DNA
• Langerhans cells initiate keratinocyte cell death
• Genetic mutations accumulate (Langerhans cells become mutated)
• Host response to UV damaged so uncontrolled cell proliferation

Question 3

What is actinic keratoses?

Answer 3

Sun exposure –> pre-cancerous lesion

Question 4

What is Marjolin’s ulcer?

Answer 4

squamous cell carcinoma that arises in an area of chronically inflamed skin

Question 5

What are other causes (risk factors) for squamous cell carcinoma?

Answer 5

• Viral infections- HPV
• Chronic skin diseases- lupus, leucoplakia
• Radiation (other)
• Carcinogen exposure- tar, cigarette smoke, soot, industrial oils
• Genetic syndromes- Gorlin’s syndrome, xeroderma pigmentosum
• Long-term immunosuppression- HIV, transplants

Question 6

Describe the epidemiology of SCC

Answer 6

• 2^nd most common cutaneous malignancy (20%) of all skin cancers
• Middle aged/ elderly
• Lighter skinned individuals
• Incidence= 1 in 4000 per year
• Male: Female= 3:1

Question 7

What is the presentation of SCC?

Answer 7

1. Patient will note skin lesion- ulcerated, bleeding and non-healing
2. History of sunbathing (or other risk factors)

Question 8

What will you see O/E?

Answer 8

Lesion will have variable appearance (usually located in sun exposed areas)-

• Hyperkeratotic
• Ulcerated
• Crusted/ scaly
• Non-healing lesion

?Lymphadenopathy

Question 9

How will you investigate a SCC?

Answer 9

1. Skin biopsy –> to confirm malignancy and differentiate between other skin lesions
2. Fine needle aspiration/ lymph node biopsy- if metastasis
3. Staging – CT/ MRI or PET

Question 10

What are the Fitzpatrick phenotypes?

Answer 10

Question 11

How do you manage SCCs?

Answer 11

Surgical excision - if surface, cryotherapy/ cauterisation

Lymph node biopsy if metastasis risk

Local radiotherapy - if surgery is difficult.

medication- topical 5-fluorouracil

Chemo for metastatic disease

Question 12

What are the complications/ prognosis of SCC

Answer 12

Metastases

Complications- squamous cell carcinomas are usually local at diagnosis. But if on linguinal membranes (lips)- likely to have spread

Prognosis- depends on location, size, level of invasion, differentiation etc.