Pigmented skin Lesions

Question 1

Ephilides

Answer 1

Freckles

Question 2

Lentigines

Answer 2

In old age patches develop

Question 3

Melanocytic naevi

Answer 3

Moles- macules, papules, plaques and nodules.

Question 4

Pathogenesis of melanocytic naevi

Answer 4

Due to an increase in basal melanocytes with downgrowths at the dermo-epidermal junction

Question 5

Congenital melanocytic naevi

Answer 5

Birthmarks- Very common.

Due to melanocytes that have failed to mature or migrate in utero.

Question 6

Acquired melanocytic naevi

Answer 6

Could be junctional, compound or intradermal.
Junctional- melanocyte nests in the DEJ
Compound- Melanocytes in the dermis and DEJ
Intradermal- Melanocytes in the dermis.

Question 7

How are congenital melanocytic naevi catergorised?

Answer 7

By size.
Small < 1.5cm
Medium 1.5-19.9cm
Large > 20cm

Question 8

Blue naevus

Answer 8

Blue looking moles. Tend to be excised because they can (rarely) become malignant.

Question 9

Atypical or dysplastic naevi syndrome

Answer 9

Lots of naevi all around the body.

Relative risk of melanoma increases with the number of atypical naevi.

Question 10

Halo naevi

Answer 10

Reaction with a decrease in melanocytes. Causes dark inner circle and pale outer circle.

Question 11

Naevus spilus

Answer 11

Birth mark esc

Question 12

Spitz naevus

Answer 12

Usually appears on the face or limbs of children and grows rapidly for months. Can be red or black/brown.

Question 13

Risk factors for melanoma

Answer 13

Genetic markers (CDKN2A mutations)
Family history
Congenital naevi
UV
Atypical or dysplastic naevus syndrome
Sunburn
Personal history of melanoma
Immunosupression
Skin type I or II
DNA repair defects

Question 14

Name the key points on diagnosing a melanoma

Answer 14

A- asymmetry- draw a line through the middle and see if both sides are equal.
B- border- regular border is likely to be benign. Irregular likely to be malignant.
C- Colour- Most benign moles are one colour. Malignancies tend to have variations.
D- diameter- greater than 4mm likely to be malignant.
E-evolution/elevation. If it changes. Likely to be malignant.

Question 15

What would a dermoscopy of a malignant melanoma show?

Answer 15

Atypical pigment networks, black dots, irregular streaks.

Question 16

Prognostic factors in melanomas

Answer 16

Depth (breslows thickness), Ulceration, number of lymoh nodes involved.

Question 17

Superficial spreading melanoma

Answer 17

Superficial melanocytes throughout the epidermis but not invasive.
Most common subtype
Usually occur in the trunk of men and the limbs of women.
Usually macule with irregular border and colour which may have been increasing in size for years.

Question 18

Lentigo melanoma

Answer 18

Neoplastic melanocytes along the basal layer which may then become invasive. Usually on the face of elderly patients with sun damaged skin.

Question 19

Nodular melanomas

Answer 19

Occurs at any body site.
Usually in older patients
Blue/black or red skin coloured nodule which may be ulcerated or bleeding and has usually developed rapidly preceding months.
No significant surrounding macular pigmentation.
Agressive growth pattern.

Question 20

Acral lentiginous melanomas

Answer 20

Usually in elderly people
Also seen in African and Asian people
Usually affects palms or soles of nails.

Question 21

Amelanotic melanoma

Answer 21

Absent or minimal visible pigment.

Question 22

Seborrheic keratosis

Answer 22

Mimics melanomas- 
They are very common. Usually occur in older caucasians. 
Black/brown greasy lesion
Often in the trunk, often multiple. 
Stuck on, warty appearance. 
Regular border.

Question 23

Treatment of seborrheic keratosis

Answer 23

Reassure patient
Freeze
Curette
Shave

Question 24

Dermatofibroma

Answer 24

Could possibly be due to insect bites

Deep dermal, brown/grey, firm nodule.

Question 25

Treatment of dermatofibroma

Answer 25

Reassure or excise.

Question 26

Talon noir

Answer 26

“black heel”

Subcorneal haematoma due to trauma.

Question 27

Treatment of melanoma

Answer 27

Surgery ASAP
1cm lateral incisional margin for every 1mm depth
To fascia at deep margin
Lymph node biopsy.