
Contents
Introduction
- Skin cancer is the most common malignancy – and the incidence is increasing rapidly
- In the last 10 years, the incidence in the UK has doubled
- Mainly seen on sun damaged / sun exposed areas of skin
- Face / head, neck, forearms, upper chest
- 95% of skin cancers are SCC or BCC
- BCC – approx 65% – with a 0.1% mortality
- SCC – approx 30% – with a 5% mortality
- <5% are melanoma – with a 10% mortality
- Skin cancers are responsible for 2% of cancer deaths each year in the UK
- 80% of skin cancer deaths are due to melanoma
- The treatment of SCC and BCC is very similar
- Melanoma requires a more definitive option
- Biopsy is generally a good idea for skin lesions if you are not sure of the origin – EXCEPT for pigmented lesions. Melanoma can be missed during a biopsy. A negative biopsy of a pigmented skin lesion does not rule out a melanoma. Surgical excision is the only suitable treatment option for suspected melanoma.
- Consider doing a full skin check in anyone with a suspicious lesion
- Be aware of new or changing lesion in mature adults
General Risk Factors
- Age
- Sun bed use
- Fair skin
- Hx of sunburn
- Hx of living overseas / or in places with a lot of sun exposure (e.g. Australia!)
- FH
- Occupations – outdoors – e.g. bricklayers, keen gardeners or cyclists
- Phototherapy
Assessing Skin Lesions
ABCDE
Use this method to approach the assessment of any skin lesion
- A – Asymmetry – break it into 2 axes
- Look for different matrices
- B – Border (irregularity)
- C – Colour – multiple different colours is bad!
- D – Diameter – >7mm
- E – Evolution / enlargement
7 point checklist for melanoma
A modified version is often used, particularly when assessing pigmented lesions for risk of melanoma. This is know as the “7-point checklist”. A score of three indicates the need for excision:
- Size >7mm
- Recent change in size of lesion
- Irregular border
- Irregular pigmentation
- Itch or irritation
- Inflammation
- Oozing or crust of the lesion
Also look out for:
- Assymetry
- “Ugly Duckling” – the lesion that really stands out compared to other lesions
The three point check-list
A simplified scale for assessing the risk of a pigmented skin lesion for melanoma
- Asymmetry – colour and structure
- Atypical Network – more than 1 type of ‘network’
- Blue / white structures – white scar-like areas, blue/grey areas, structureless areas
An abnormality in any of these areas is worth one point
- 0 or 1 – likely benign
- 2 or more – needs excision / removal – high risk for melanoma
Example
Here is a melanoma. Note its asymmetry when split into 4 quadrants. Note that there are different types of pigmentation (different ‘networks’). There is not any obvious scarring nor blue-white structures. The border is very irregular. It is likely to be larger than 7mm. There is no inflammation, and no oozing or crust.
- On the 7 point checklist – this scores a 3 on appearance along, and maybe a 5 if recent change in size or itch – LIKELY MELANOMA
- On the 3 point checklist – this lesions scores a 2 – LIKELY MELANOMA

Squamous Cell Carcinoma
Risk Factors
- Smoking
- Sun Exposure
- Presence of premalignant lesions (actinic keratosis)
- Age
- Skin trauma
- Exposure to carbon containing compounds
- Asbestos
- Arsenic
- Ionizing radiation
- Metals
- Non-solar UV radiation – e.g. welders
- 3x more common in men
- Occupational – e.g. builder / farmer – associated with chronic low-grade sun exposure
Presentation
- Solitary papule / nodule, often eroded at the centre, or crusty, purulent or bleeding
- Usually a ‘fleshy’ lesion
- May resemble giant warts, but, unlike warts, may be painful
- Usually in a sun-exposed area
- Often hard, scaly, dome-like structures
- Can bleed or itch
- Also related to smoking, and may be present on the lower lip
- Bowen’s disease = SCC in situ (hasn’t yet spread)
Treatment
- The definitive treatment is surgical excision with minimum 2mm margin
- Excision with wide surgical margins
- Small tumour – 2-4mm margin
- Normal margin – 5mm – success rate – 95%
- High risk tumour site – not exposed to sun, lips, anus. These need larger excision to reduce the risk of metastasis (10mm margin)
- Many can be treated with topical cream
- 5-fluorouracil is the recommended treatment – applied 1-2x daily for 4 weeks (max 12 weeks)
- Immiquimod – applied once daily, 5x a week fo rum to 6 weeks is an alternative
- Can cause scarring
- You don’t get a histological diagnosis
- You can never be sure if it has been completely fully treated
- May also be treated with cryotherapy (liquid nitrogen). Similar risks to topical cream treatments – particularly can cause scarring especially if used on the face – be careful!
- Metastases – rare
- Lymph nodes
- Solar keratoses
- These are superficial precursors to SCC
- Often in sun exposed areas
- Can be treated with topical agents or cryotherapy
- Often only require a short burst of cryotherapy – 1-2 cycles of 8-10 seconds each
Examples

Melanoma
- Proliferation of atypical melanocytes with potential for dermal invasion and widespread metastases
- Sun exposure still a risk factor, but not as important as SCC or BCC. Other risk factors include:
- Male Gender
- >50 “moles” (benign naevi)
- FHx of melanoma
- Fair complexion
- Smoking
- 70% arise from normal skin, 30% arise from pre-existing naevi
- Women – Common on lower legs. Women tend to present sooner for many reasons – they tend to be better at checking their skin, and more concerned about skin lesions.
- Men – Common on back
Epidemiology
- Most dangerous type of skin cancer – highest mortality of the three main types of skin cancer
- Most likely to metastasize
- Men – about 1/14 lifetime risk (in Australia)
- Women – about 1/24 lifetime risk (in Australia)
- Only account for about 3% of skin cancers
- 4th most common type of cancer in Australia
- Australia has the highest incidence of melanoma in the world
- Incidence 52 per 100 000 in Australia
Risk Factors
- Family history of melanoma – doubles your risk
- Skin Type – White skin vs black skin – 19x risk
- Age – 70yo men 10x risk of 30yo men
- PMHx melanoma – 10x risk
- Recurrence most likely to occur in the first 5 years
- Multiple Naevi (‘moles’) – >100 – 7x risk (compared to someone with <15 moles)
- >50 naevi is significant
- Sun – UVB is the main type of UV ray causing melanoma risk – compared to UVA which is more likely to cause BCC or SCC
- Previous Sun burn – 2x risk
- Previous other skin cancers (BCC or SCC) then 4x the risk of background
- Giant congenital naevus >20cm
- Red hair freckles skin types
- Sun exposure – particularly sunburn before the age of 10
Pathology
- Melanocytes derived from neural crest cell.
- The normal life cycle of a melanocyte is to gradually shrink in size and lose melanin producing abilities before they die
- If there is a mutation then the cell can start to proliferate and divide and grow in size
- 50-70% arise de novo. The rest present at the site of existing ‘moles’
- The average Caucasian has 30 moles
- You are born with only 1-2
- Most are acquired in teenage years
- New moles after the age of 40 are worrying!
- Caution during pregnancy!
- Malignant melanoma is no more common during pregnancy
- Moles can change size and become darker during pregnancy
- Rare sites for lesions include mucosa (particularly in the anal region), genital regions and conjunctiva
Types of melanoma
- 15% of cases of melanoma
- Usually on the face (or other sun exposed areas) in elderly patients
- Typically a large, flat, dark lesion
Superficial spreading melanoma
- About 65% of melanomas
- Most commonly on the legs of women, and the torso/back of men
- Appears like a slightly raised plaque
Nodular Melanoma
- 10-15% of cases
- Anywhere on the body
- Often dark coloured
- Occasionally may be pearly or lack pigment
- Very rarely metastasise, but grow rapidly
Acral and subungal melanoma
- Relatively rare, but the most common melanoma in Black Africans
- Usually seen on the palms or soles, or subungal skin (under fingernails)
Spread
- Local lymph nodes
- Satellite lesions – usually nearby, nodules or papules that may or may not be pigmented
- Skin
- Internal organs – rare
Treatment
- Excision is the only treatment
- Margins are guided by the extent of spread (depth) on histology. Usually a 2mm margin is taken at the original excision, and sent for histology. Then, when results are available, re-excise the site with the following suggested margins:
- Melanoma in situ – 5-10mm margin
- Melanoma <1mm thick – 10mm margin
- 1-4mm thickness – 10-20mm margin
- >4mm thickness – 20mm margin
- This thickness is referred to as the Breslow depth
- Margins laterally and should be removed down to the fascia (including all subcutaneous fat)
- Examine lymph nodes and for organomegaly
- >4mm depth of tumour has >60% chance metastasis
- Do NOT biopsy pigmented skin lesions – the melanoma itself can be missed in an area of naevus – not good for patient (or later on for doctor!)
- Biopsy of local lymph nodes recommended for melanoma of depth >1mm
Prognosis
- This is correlated to the depth of dermal spread, and to the histological appearance. The Breslow depth is a scale often used as a prognostic indicator:
Tumour Thickness (mm) | 5-Year Survival |
<0.76 | >98% |
0.76 – 1.5 | 90% |
1.51 – 2.25 | 83% |
2.26 – 3.0 | 75% |
>3 | 45% |
Chemotherapy / radiotherapy and surgical removal of nodes may be required if there is spread to lymph nodes
Follow Up
- <1mm thickness – 6 monthly for 2 years
- 1-2mm thickness – 4 monthly for 2 years, 6 monthly for 2 years, yearly for 10 years
- >2mm thickness – annual CXR and regular GP and specialist FU
Examples
Basal Cell Carcinoma – BCC – aka Rodent Ulcer
Risk factors
- Fair skin
- Sun exposure – accumulative lifetime exposure
Presentation
Can be highly variable
- Usually nodular
- May be erythematous, or non-pigmented
- May be plaque-like
- May be ulcerated
- They can sometimes crust over, and apparently undergo some healing and reduction in size, but generally, enlargement is slowly progressive.
Treatment
- Surgical excision is treatment of choice
- 3mm margin usually adequate
- Can also be treated topically
- 1st is Imiquimod – applied once daily, 5 days a week for up to 6 weeks
- Do NOT treat topically if on head or neck – these need surgical excision
- Cryotherapy may also be suitable for smaller, superficial well defined lesions
Like with SCC:
- Topical agents
- Can cause scarring
- You don’t get a histological diagnosis
- You can never be sure if it has been completely fully treated
Examples



Other Types of Skin Lesion
Seborrhoeic Keratoses
- Crusty
- Often luck like they are ‘stuck on’
- Like barnacles!
- Are benign and can be left alone. Patient may decide they don’t like the appearance, or it may catch on clothing, or it may be itchy or irritating – all of which are reasonable indications for removal
- Can shave off. Can use curettage (burn off)
- Can cut off / frozen off
- Not usually treated with topical agents
- May be mistaken for melanoma as they are often pigmented
Examples


Campbell de Morgan Spots
- Red spots that occurr over body with age
- Benign
- Sometimes raised
- Sometimes Flat
Solar Keratoses (aka actinic keratosis)
- Sun damaged
- Pre cancerous – can turn into SCC
- Often red and scaly
- Can treat with cryotherapy or Effudix (5-fluorouracil)

Dermatofibroma
- Central scare like area with peripheral light brown network
- Benign
Congenital naevus
- “Cobblestone” pattern
- Usually develop early in life
Reticular Naevi
- Benign
- What a lay person would most likely call a ‘mole’
Blue Naevi
- Homogenous blue coloration. Often very Dark coloured
- Usually very symmetrical and very well defined borders
- Usually solid block of colour
Three types of pattern
- Reticular Pattern
- Cobblestone pattern
- Homogenous blue
- Is it symmetrical pattern and homogenous colour?
Special Naevi
- Acral Naevus – often on the fingers. Wither dermatoscope often has well defined ‘furrows’ and ‘ridges’