Melanomas which appear on intermittently sun-exposed skin are most likely to have which type of mutation?
(upregulates MEK and ERK which drive cell proliferation)
During embryogenesis, melanoblasts migrate to which regions of the body?
What are the leptomeniges?
Pia mater and arachnoid
Which types of melanoma grow as macules?
What is Brelow's thickness?
The deepest part of a skin tumour as measured from the granular layer
Acral melanomas are associated with which mutation type?
What is the MC1R protein and what is its function?
Melanocortin 1 receptor gene
Determines balance of pigment in hair and skin by converting pheomelanin to eumelanin
Most cases of melanoma arise ___________
Most cases of melanoma arise denovo
If a melanoma is invasive and >1mm thick, how should it be excised?
Excise with 2cm clearance and sentinel node biopsy
If a melanoma is foudn to be in-situ, how is it excised?
What is the most common type of melanoma?
Superficial spreading melanoma
Where does superficial spreading melanoma normally affect on the skin?
Trunk and limbs
How can dysplastic naevi be described?
Naevi >6mm in diameter with varigated pigment and border asymmetry
Which type of naevus constits of pigment-rich dendritic spindle cells and is located in the dermis?
Which type of naevus involves the destruction of melanocytes and high concentrations of lymphocytes which contribute to this destruction?
How are halo naevi created?
Autoimmune reaction against a naevus on the skin
Lymphocytes destroy the naevus causing it to become lighter in colour, turining pink and then eventually disappearing entirely
The immune reaction destroys surrounding melanocytes which gives the halo appearance
Age spots are known by which other name?
What are age spots due to?
Long term UV exposure
Where are melanocytes dervied?
For which reason do freckles occur after sun exposure?
Reflect the clumpy distribution of melanocytes in the skin
For freckles to be present a person requires a mutation in which gene?
MC1R (only one copy)
Which naevus can mimic melanoma?
Which may a Spitz naevus be dangerous?
Most are benign but there is a malignant variant
In which skin layer do melanocytes reside?
How many types of melanoma exist?
What are the four main types of melanoma?
- Superficial spreading
- Acral/mucosal lentiginous
- Lentigo maligna
Familial dysplastic naevi have which lifetime risk of melanoma?
Up to 100%
Which suffix in Breslow's thickness indcates ulceration?
What are the stages of Breslow's thickness?
pTis - In situ
pT1 - <1mm
pT2 - 1-2mm
pT3 - 2-4mm
pT4 - >4mm
What risk do large malanocytic naevi pose to becoming melanomas?