Skin Cancer

Question 1

What are the two different types of skin cancer

Answer 1

Melanoma

Non melanoma skin cancer (NMSC) - basal cell carcinoma and squamous cell carcinoma

Question 2

Where do melanomas arise from?

Answer 2

They arise from melanocytes which migrate to the skin from the neural crest
Melanocytes are found in the basal layer of the epidermis in the dermal epidermal junction

Question 3

What are the different survival rates on melanoma tumour depth?

Answer 3

Breslow thickness of less than 1mm has a 95-100% survival rate
Breslow thickness of over 4mm has a 5 year survival rate of 50%
Metastasis of melanomas have a 5 year survival rate of 5%

Question 4

What are the ABCDE of melanomas?

Answer 4

A = asymmetry 
B = border 
C = colour 
D = diameter 
E= evolution

Question 5

What are the characteristics of basal cell carcinoma?

Answer 5

Slow growing lump or non healing ulcer 
Painless 
Locally invasive but rarely spreads
Pearly or translucent appearance 
Visible blood vessels 
Central ulceration

Question 6

What are the different types of basal cell carcinoma

Answer 6

Scaly plaque - superficial
Nodules
Infiltrative - morpheic
Pigmented

Question 7

What are the characteristics of squamous cell carcinoma

Answer 7

Warty or crusted lump or ulcer 
Arises on sun damaged skin 
Grows very fast 
Painful
Bleeds 
Hyperkeratotic 
Low chance of mets

Question 8

What are the different types of squamous cell carcinoma

Answer 8

Precursor lesions - actinic keratosis
Bowens disease (carcinoma in situ)
Keratocanthoma- self resolving

Question 9

What are the high risk sites for development of SCC

Answer 9

Ears
Lip
Scalp

Question 10

What are the risk factors for skin cancer?

Answer 10

Sun exposure
Genetic predisposition
Immunosuppression
Environmental carcinogens - coal tar, smoking, ionising radiation, arsenic, trauma, chronic ulceration

Question 11

What are the different types of conditions that have genetic susceptibility?

Answer 11

DNA repair syndromes - xeroderma pigmentosum
Albinism
Naevoid basal cell carcinoma (gorlins)
Epidormolysis bullosa

Question 12

What are the symptoms and mechanism of xeroderma pigmentosum?

Answer 12

Photosensitivity
Skin cancer on UV exposed sites
Neurological degeneration
Increased risk of other cancers

Defect in nucleotide excision repair

Question 13

What is the inheritance and symptoms of Gorlin’s syndrome?

Answer 13

Autosomal dominant 
Early onset BCC 
Palmar pits 
Jaw cysts 
Ectopic calcification falx

Question 14

What conditions can lead to immunosuppression that predisposes to skin cancer?

Answer 14

Organ transplant recipients - SCC increased
Haematological malignancies e.g. Chronic lymphatic leukaemia
Inflammatory conditions requiring immunosuppressive therapies e.g. IBD, RA, vasculitis
HIV/ AIDS

Question 15

What can be done to help prevent skin cancer?

Answer 15

Behaviour - avoid sunlight at peak, use shade, care of babies, avoid sun beds
Clothing - dark tightly woven loose fitting clothes
Sunscreens - broad spectrum (25+ SPF) with UVA protectoin
Regular self surveillance