Skin Cancer Flashcards
2 main types of skin cancer
Keratinocyte skin cancer - basal cell carcinoma and squamous cell carcinoma
Melanoma
Why may the incidence of non-melanoma skin cancer in Scotland be increasing?
Cheap air travel
More leisure time
Sun-seeking behaviour
Ageing population
What does melanoma arise from?
Melanocytes - pigment forming cells scattered along the basal layer
Which skin cancer is most likely to spread - keratinocyte skin cancer or melanoma?
Melanoma as melanocytes migrate into the skin from the neural crest and move around
What does melanoma survival depend on?
Breslow thickness
What is Breslow thickness?
The measurement of depth of the melanoma from the surface of the skin to the deepest point of the tumour
5 year survival of melanoma with:
- Breslow thickness <1mm
- Breslow thickness >4mm
- Metastases
<1mm = 95-100% >4mm = 50% Metastases = 5%
Diagnosis of melanoma
ABCDE rule
“ugly duckling” sign
Dermoscopy
ABCDE rule in diagnosis of melanoma
A = asymmetry B = border C = colour (change of colour or presence of 2/3 different) D = diameter (>0.7mm is likely to be melanoma) E = evolution (speed of change, changing over weeks/months)
“Ugly duckling sign”
The mole suspected as being a melanoma looks very different to all other moles
Why is dermoscopy useful in the diagnosis of melanoma?
It allows us to see a magnified view showing pigment pattern
Atypical mole syndrome
Genetic condition where patients have multiple atypical moles. These patients are more likely to develop melanoma but are harder to monitor as they have so many moles
Clinical presentation of basal cell carcinoma
Slow growing lumps or ulcers that are painless
‘Pearly’ or translucent
Visible, arborising blood vessels
Central ulceration
Locally invasive but rarely metastasise
Can look scar-like with ill-defined edges
Different types of basal cell carcinoma
May present as scaly plaque - superficial
Nodular or nodulystic
Infiltrative - “morphoeic”
Pigmented
Clinical presentation of squamous cell carcinoma
Hyperkeratotic (crusty) lump or ulcer
Arises on sun damaged skin - often seen in elderly
Grow fairly fast
May be painful and/or bleed
Risk of metastases of squamous cell carcinoma
3-5%
Common sites for squamous cell carcinoma (higher risk)
Ear, lip, scalp
Keratoacanthoma
Self resolving squamous cell carcinoma
Precursor lesions for squamous cell carcinoma
Actinic keratosis
Bowen’s disease - carcinoma in situ
Where to squamous cell carcinomas tend to spread to when they metastasise?
Lymph nodes and bone
Rarer sites for squamous cell carcinoma
Chronic ulceration/wounds/scarring
Actinic keratoses
Pre-cancerous skin lesions. Precursors for non-melanoma skin cancers
What do actinic keratoses tell us about the skin?
That the skin is damaged
Actinic keratoses are highly associated with the risk of developing what?
Squamous cell carcinoma or basal cell carcinoma
What is Bowen’s disease?
Carcinoma in situ