Skin Cancer

Question 1

What is a basal cell carcinoma

Answer 1

A non-melanoma skin cancer arising from keratinocytes in the epidermis

Question 2

Sun exposure pattern commonly causing BCC

Answer 2

intermittent, intense sunburn episodes

Question 3

Most common skin cancer

Answer 3

BCC

Question 4

Presentation of BCC

Answer 4

painless slow growing lump or non-healing ulcer

“stuck on” appearnace

pearly border

central ulceration - rodent ulcer

telangiectasia - visible, aborising blood vessels

Question 5

Types of BCC

Answer 5

nodular
superficial
infiltrative

Question 6

Spread of BCC

Answer 6

no mets

Question 7

Tx of BCC

Answer 7

surgical excision

Question 8

What is a squamous cell carcinoma

Answer 8

Non-melanoma skin cancer arising from keratinocytes in the epidermis

Question 9

Sun exposure pattern of SCC

Answer 9

chronic, cumulative UV exposure

Question 10

Precursor lesions of SCC

Answer 10

1. Actinic keratoses
   - epidermal dysplasia
2. Bowens disease
   - slow growing red, scaly plaque
   - squamous dysplasia

Question 11

Presentation of SCC

Answer 11

hyperkeratotic (crusted) lump or ulcer

relatively fast growing

Question 12

What is a cutaneous horn

Answer 12

compact keratin that has grown
ear, lip and scalp are high risk sites
can be a SCC

Question 13

Tx of SCC

Answer 13

Surgical excision -
4mm margins if diameter <20mm
6 mm margins if diameter >20mm

Mohs surgery -
high risk patient or cosmetically important site

Question 14

What is a malignant melanoma

Answer 14

Tumour arising from the melanocytes in the basal layer of the epidermis

Question 15

Signs that would make you suspect melanoma

Answer 15

change in shape
irregular pigmentation
bleeding
development of satellite nodules (tumour nodules appearing > 0.5mm from the primary lesion)
ulceration
new pigmented lesion developing in adulthood

Question 16

4 main types of melanoma

Answer 16

1. superficial spreading
2. acral/mucosal lentiginous
3. lentigo maligna
4. nodular

Question 17

What is radial growth phase (RGP) of malignant melanoma

Answer 17

tumour grows as macule/patch - everything is above the epidermal basement membrane - so there are no vessels for the melanoma to get into and spread

Question 18

What is vertical growth phase (VGP) of malignant melanoma

Answer 18

Invasion of melanoma cells vertically into dermis, forming an expansile mass. Tumour has metastatic potential.

Question 19

What types of melanoma have a RGP

Answer 19

Acral/mucosal lentiginous
Lentigo maligna
Superficial spreading

Question 20

What types of melanoma only have a VGP

Answer 20

Nodular melanoma

Question 21

How is prognosis of melanoma determined

Answer 21

Tumour depth - Breslow thickness

< 1mm depth: 95-100% 5 year survival
> 4mm depth: 50% 5 year survival
Metastases: 5% 5 year survival

Question 22

‘ugly duckling sign’

Answer 22

all moles are light brown except one - sign of malignant melanoma

Question 23

Ix for suspected malignant melanoma

Answer 23

simple dermatoscopy, then
skin biopsy

+/- sentinal node biopsy if suspicion of metastatic disease

Question 24

ABCDE rule for moles

Answer 24

Asymmetry 
Border 
Colour
Diameter
Evolution

Question 25

Tx of melanoma

Answer 25

1. surgical excision 2. Imiquimod (aldara cream) +/- sentinel node biopsy from Stage 1 onwards

Question 26

Most common presentation of Bowen's disease

Answer 26

Elderly female | Lower legs most common area

Question 27

Tx of Bowen's disease

Answer 27

Topical 5 fluoro-uriacil (Efudix) or Imiquimod (Aldara)

Question 28

What is a Marjolin Ulcer

Answer 28

aggressive SCC that occurs at the site of ulceration or trauam

Question 29

Risk factors for developing SCC

Answer 29

Immunocompromisation - e.g. transplant patients, HIV excessive exposure to sunlight / psoralen UVA therapy actinic keratoses and Bowen's disease smoking