Melanoma and naevi

Question 1

Patch of malignant melanocytes proliferating radially along the dermo-epidermal junction

Answer 1

Lentigo maligna (Hutchinson’s malignant freckle)

Question 2

What name is given to the type of melanoma when a portion of lentigo maligna becomes invasive?

Answer 2

Lentigo maligna melanoma

Question 3

Commonest type of melanoma in the UK?

Answer 3

Superficial spreading melanoma (SSM)

Question 4

Describe the growth pattern of SSM?

Answer 4

Radial growth followed by true vertical invasion

Question 5

Clinical features of SSM? (3)

Answer 5

Irregularly bordered/pigmented
May itch/be painful
May bleed

Question 6

Type of melanoma which exhibits an invasive growth pattern from the outset?

Answer 6

Nodular melanoma

Question 7

Pigmented patch on the sole/palm/subungual, seen more commonly in Asian/Afro-Carribean populations

Answer 7

Acral melanoma

Question 8

What history features should alert to the possibility of melanoma? (7)

Answer 8

Growth in an existing mole/development of a new one 
Irregular outline
Irregular pigmentation
Larger than 6mm diameter
Reddish edge 
Bleeding, oozing or crusting lesion
Itchy/painful lesion

Question 9

Main determinant of prognosis in melanoma?

Answer 9

Breslow thickness- depth of tumour invasion.

Question 10

What is the risk of possessing congenital melanocytic naevi?

Answer 10

Smaller ones have a slightly elevated melanoma risk later in life; larger naevi (e.g. a giant congenital melanocytic naevus) have a high risk

Question 11

Diffuse blue-black patch on the lower back/buttocks of child

Answer 11

Mongolian blue spot, a type of congenital melanocytic naevus

Question 12

Phases of an acquired melanocytic naevus (3)

Answer 12

Junctional
Compound
Intradermal

Question 13

When do most melanocytic naevi appear?

Answer 13

In the first 20 years of life

Question 14

What is the clinical importance of acquired melanocytic naevi? (3)

Answer 14

Some malignant melanomas develop in a pre-existing naevus
Large numbers of acquired melanocytic naevi is associated with increased melanoma risk
Melanocytic naevi can be confused with melanoma

Question 15

Other types of acquired melanocytic naevi (4)

Answer 15

Sutton’s halo naevus
Dysplastic naevus
Blue naevus
Spitz naevus (characteristic brick red colour)

Question 16

Types of vascular naevi (3)

Answer 16

Superficial capillary naevus (stork mark)
Deep capillary naevus (port-wine marks)
Childhood angioma (strawberry naevus)

Question 17

Specific indications for treatment in childhood angioma (4)

Answer 17

Obstruction of feeding/breathing
Obstruction of vision/proximal to eye
Severe bleeding
If it remains unsightly after age of 10

Question 18

Pharmaceutical options for management of childhood angioma (2)

Answer 18

Prednisolone

Propanolol

Question 19

What are the ABCD criteria for assessing melanocytic skin lesions?

Answer 19

Asymmetry
Border (irregular)
Colour (heterogeneous)
Diameter (>6mm)

Question 20

What is the 5y survival for melanoma in C?

Answer 20

100%

Question 21

Management options for melanoma treatment (4)

Answer 21

Imiquimod (in situ lesions only)
Excision
Completion lymphadenectomy
Adjuvant radiotherapy

Question 22

Benign reasons for changes in moles? (3)

Answer 22

Guttate psoriasis over mole
Atopic eczema over mole
Depigmentation leading to halo naevus

Question 23

What is the reason for the appearance of blue naevi?

Answer 23

Migration of melanocytes in development stopped “too soon”- cluster of cells remaining in the dermis makes it look blue

Question 24

Name given to familial tendency to have many unusual naevi?

Answer 24

Dysplastic naevus syndrome

Question 25

What is the pathway from solar lentigo to lentigo maligna melanoma?

Answer 25

Solar lentigo acquires malignant mutation and enters radial growth phase –> lentigo maligna
Lentigo maligna enters vertical growth phase –> lentigo maligna melanoma

Question 26

What treatment is available for large lentigo maligna which are still in radial growth?

Answer 26

Imiquimod

Question 27

What is the “starburst” appearance under dermoscopy indicative of?

Answer 27

Changing mole

Question 28

Which groups of people are more likely to develop amelanotic melanoma?

Answer 28

People with very fair skin