Pathology 2

Question 1

Normal melanocytic development

Answer 1

-Derived from the neural crest, melanoblasts migrate from neural crest to skin then settle and cause melanocytes in basal layer

Question 2

what gene determines the balance of pigment in skin and hair?
-name for red and non red hair?

Answer 2

MC1R gene, encodes MC1R protein

-Phaeomelanin, Eumelanin

Question 3

what causes freckles?

Answer 3

patchy increase in melanin pigmentation after UV expire, clumpy distribution of melanocytes.

Question 4

What are actinic lentigines

Answer 4

age spots due to UV exposure

Question 5

Melanocytic naevi

• types (2)
• name the 3 ways in which a nevus develops

Answer 5

-congenital and acquired

-junctional naevus, clusters of melanocytes at DEJ
compound naevus, junctional clusters ad groups of cells in dermis
intra-dermal naevus, entirely in the dermis

Question 6

Dysplastic naevi

• features (3)
• features of sporadic (3) and familial (3) dn
• monitering

Answer 6

->6mm in diameter, varied pigmentation, border asymmetry

-Sporadic
not inherited
1-7 atypical naevi
risk mm slightly raised

Familial
strong FH melanoma
many atypical naevi
v high risk of melanoma

-photos

Question 7

Halo naevi, give 3 features

Answer 7

peripheral halo depigmentation
inflammatory regression
over run by lymphocytes

Question 8

Blue naevi features (2)

Answer 8

entirely dermal and consist of pigment rich spindle cells

Question 9

spitz naevus features

-appearance

Answer 9

benign juvenile melanoma, large spindle epithelial cells

-dome shaped vascular papule

Question 10

Malignant melonoma

• aetiology
• most common sites
• 6 features of suspicious lesion
• name the 4 main types
• prognosis determined by? (6)
• spread?
• management
• genetics related pharmacological therapy?

Answer 10

• sunburn in childhood, genetic risk- skin type
• scalp, face, neck, arm, trunk, leg

-new pigmented lesion in adulthood
change in shape
irregular pigmentation
bleeding 
satellite nodules
ulceration

-superficial spreading (begin in situ, RGP then eventually VGP into dermis and mets)
Acral/mucosal “”
Lentigo maligna””
Nodular (VGP, aggressive)

-Breslow depth and ulceration
also high mitotic rate
lymphovascular invasion
satellite nodules
lymph nodes

-vascular spread to skin, heart, lungs, liver, brain

-Primary excision to give clear margins
sentinal node biopsy
chemo and radio of mets

-Imitinab
if BRAF mutation then dabrafenib/vemurafenib

Question 11

How to describe a skin lesion?

Answer 11

ABCD
Asymmetry
Border
Colour
Diameter