Naevi

Question 1

What is a naevus?

Answer 1

Benign lesion/proliferation of one or more normal constituent cells of skin

Question 2

What are naevi classified as? (2)

Answer 2

• Melanocytic/pigmented naevi

- Vascular naevi

Question 3

What are the common properties of melanocytic naevi? (5)

Answer 3

• Very common
• Usually multiple
• Pigmented
• Benign
• Appear in childhood/adolescence

Question 4

List the melanocytic naevi variants (5)

Answer 4

• Congenital naevi
• Junctional naevi
• Intradermal naevi
• Cafe au lait spots
• Mongolian spots

Question 5

What are melanocytic naevi also known as?

Answer 5

Moles

Question 6

Describe the appearance of intradermal naevi (3)

Answer 6

• Dome shaped
• Skin coloured
• Papules

Question 7

What determines whether a melanocytic naevus is junctional, compound or intradermal?

Answer 7

The site of naevus cells

Question 8

Describe the distribution of naevus cells in intradermal naevi? (3)

Answer 8

• Localised/confined in the dermis (below most external layer of skin)
• More organised
• Limited junctional involvement

Question 9

Identify intradermal naevus

Answer 9

See picture

Question 10

Identify intradermal naevus histologically

Answer 10

See histology picture

Question 11

Describe the appearance of junctional naevi (3)

Answer 11

• Flat
• Macules
• Round/oval

Question 12

Where are intradermal naevi usually found?

Answer 12

Face

Question 13

Where are junctional naevi usually found? (3)

Answer 13

• Soles
• Palms
• Genitalia

Question 14

Identify junctional naevus

Answer 14

See picture

Question 15

Identify junctional naevus histologically

Answer 15

See histology picture

Question 16

When do congenital naevi appear?

Answer 16

Birth - first 2 years

Question 17

What determines the shape of a naevus?

Answer 17

Distribution of melanoyctes

Question 18

Describe congenital naevi (4)

Answer 18

• Larger
• Irregular border
• Thickness
• Hairy

Question 19

Do congenital naevi have a risk of malignant change?

Answer 19

Yes, a small risk - need monitoring but mostly not serious

Question 20

Describe the distribution of nevus cells in junctional naevi? (3)

Answer 20

• Flat so band distribution of melanocytes in epidermis

- Smaller clusters going down

Question 21

How do benign lesions appear histologically?

Answer 21

• Progressive maturation of melanocytes

- Plumper at top, smaller and organised at bottom

Question 22

List the vascular naevi (3)

Answer 22

• Angel kiss/stork mark
• Infantile haemangioma
• Port wine stain

Question 23

When do infantile haemangiomas normally appear?

Answer 23

Shortly after birth

Question 24

Blister causes

Answer 24

• Friction
• Insect bites
• Heat
• Oedema blisters
• Infection - viral/scabies/bullous impetigo

Question 25

3 infectious causes of blister

Answer 25

- Viral - Scabies - Bullous impetigo