Benign and malignant melanocytic lesions

Question 1

What is the single most important risk factor for melanoma?

Answer 1

UV exposure

- episodes of sunburn

Question 2

Risk factors for melanoma?

Answer 2

• FH
• previous melanoma
• severe sunburn in childhood
• increased UV exposue
• atypical moles (multiple dysplastic naevi)
• large congenital naeve

Question 3

Where are melanocytes found?

Answer 3

Basal layer of epidermis

Question 4

What are freckles?

Answer 4

increased number of melanocytes (increase in UV exposure)

Question 5

What is a mole made up of?

Answer 5

nest of melanocytes

Question 6

What is a junctional naevus and what does it look like?

Answer 6

acquired moles in late childhood/early adolescence

flat and dark

Question 7

What is a compound naevus and what does it look like?

Answer 7

The nests migrate deeper into the dermis, so the melanocytes are in the dermis and epidermis
Dome shaped brown papule

Question 8

What is an intradermal naevus?

Answer 8

Dome shape skin coloured, when it goes further into dermis

Question 9

What are the stages in the evolution of a mole?

Answer 9

• junctional naevus
• compound naevus
• intradermal naevus

Question 10

What are atypical naevi?

Answer 10

Atypical mole, looks like a melanoma but benign
Can be asymmetrical, large and different colours
Often excised as cannot distinguish

Question 11

Aetiology of atypical moles?

Answer 11

• genetic

- childhood sun exposure

Question 12

Prevalence of atypical moles?

Answer 12

2-5%

Question 13

Risk of atypical moles?

Answer 13

high risk of getting melanoma esp if >50 or with family history

Question 14

2 other types of acquired naevi?

Answer 14

• halo naevus

- blue naevus

Question 15

What is a congenital naevus?

Answer 15

Present from birth
Less common than acquired
Can vary in size

Question 16

What is the 7 point checklist for a melanoma?

Answer 16

Major features:

• changing colour
• changing size
• changing size

Minor features:

• bleeding
• inflammation
• itching
• > 7mm in size

Question 17

How do we describe a melanoma?

Answer 17

Asymmetry
Border
Colour
Diameter
Elevation

Question 18

Different types of melanona?

Answer 18

In situ melanoma:
- lentigo maligna
- melanoma in situ
Invasive melanoma
- superficial spreading
- nodular melanoma
- lentigo maligna
- acral melanoma

Question 19

What is a lentigo maligna?

Answer 19

• malignant cells confined to epidermis
• sun exposure sites
• v long hx of increased size, change in shape and colour
• often starts as a large freckle (lentigo)
• can become malignant if not treated

Question 20

Most common type of invasive melanoma?

Answer 20

• superficial spreading - 70%

- thin and expands radically

Question 21

What does a nodular melanoma look like and what is its prognosis?

Answer 21

• raised from the skin
• tends to be thick and invade vertically
• poorer prognosis
• rare

Question 22

Which type of malignant invasive melanoma is more common in dark skin?

Answer 22

• acral melanoma
• invades rapidly
• Bob marley died of this!!!

Question 23

What does the prognosis of melanoma depend on?

Answer 23

Depth of invasion - Breslow thickness
5 y survival 
- in situ 100%
- <1mm 95%
- 1-3mm 70%
- >3mm 40% or less

Question 24

Possible ddx of melanoma?

Answer 24

• seborrhoeic wart
• pigmented BCC
• dermatofibroma
• pyogenic granuloma
• atypical mole
• blue naevus

Question 25

Management of melanoma?

Answer 25

Wide local excision using 1-2cm peripheral margin
- depends on tumour thickness

Lymph node clearance for regional metastasis - sentinel node biopsy

Question 26

What is the management for metastasis?

Answer 26

Chemotherapy, radiotherapy, immunotherapy through oncology and MDT