Skin Cancer Flashcards
What are the 2 main groups of skin cancers?
Melanoma
Non-melanoma
What are the 2 main non-melanoma skin cancers?
Basal cell carcinoma
Squamous cell carcinoma
Non-melanoma skin cancers arise from which skin cells?
Keratinocytes
Melanoma skin cancers arise from keratinocytes. True/False?
False
Arise from melanocytes
Melanoma is the fastest increasing cancer in Scotland. True/False?
True
Squamous cell carcinoma is more common than basal cell carcinoma. True/False?
False
Melanoma is the most common cancer in 15-24 yr olds. True/False?
True
Melanoma is 2x more common in which sex?
Females
What determines prognosis in melanoma?
Depth of the melanoma
What is the % survival for melanoma lesions less than 1mm over 5 years?
95-100%
Thinner melanomas have better prognosis than thicker ones. True/False?
True
What is the ABCDE approach to diagnosing melanoma?
Asymmetry Borders Colour Diameter Evolution
If a mole is fast-growing and very dark black, it is not worrying. True/False?
False
Basal cell carcinomas are fast-growing. True/False?
False
Slow-growing due to poor blood supply
Are basal cell carcinomas usually painful?
No
Describe the appearance of basal cell carcinoma
Pearly/translucent lump
Aborising blood vessels
Central ulceration
What is the most common cause of squamous cell carcinoma?
Sun-damaged skin
Squamous cell carcinoma is fast-growing. True/False?
True
Relatively fast compared to BCC
Both basal and squamous cell carcinomas are likely to metastasise. True/False?
False
Basal cell carcinoma is localised
Describe the appearance of squamous cell carcinoma
Hyperkeratotic lump/ulcer
May be painful/bleed
Name 2 precursor lesions that can lead to squamous cell carcinoma
Bowen’s disease
Actinic keratosis
How do actinic keratoses arise?
Sun damage
High risk of developing squamous cell carcinoma
Describe Bowen’s disease
Erythematous plaque - very early form of squamous cell carcinoma that is easily treated
List risk factors for skin cancer
Sun exposure
Genetics
Immunosuppression
Environmental carcinogens
Describe skin type I
Always burns, never tans
Describe skin type II
Usually burns, can tan
Describe skin type III
Usually tans, can burn
Describe skin type IV
Always tans, never burns
Describe skin type V
Brown skin
Describe skin type VI
Black skin
List 3 genetic diseases that increase risk of skin cancer
Xeroderma pigmentosum
Albinism
Naevoid basal cell carcinoma (Gorlin’s syndrome)
What is xeroderma pigmentosum?
Photosensitivity disease where skin cancer can occur on UV-exposed sites
Defect in NER genes
What is Gorlin’s syndrome?
Autosomal dominant disease featuring multiple basal cell carcinomas
Which UV radiation is the most lethal - UVA, UVB or UVC?
UVC
Then UVB then UVA
What blocks out UVC radiation so that we are never exposed to it?
Ozone layer
What protects us from UVB radiation?
Window glass
Some sunscreen
What is the effect of UV radiation upon DNA?
Damages DNA and causes mutations
What is the signature DNA mutation of UV radiation?
Pyrimidine dimer mutation
Skin type I individuals have which type of melanin instead of eumelanin which doesn’t absorb UVR effectively?
Pheomelanin
MC1R protein determines balance of pigment in skin and hair. What would 1 or 2 mutations in the MC1R gene cause respectively?
1 mutation causes freckling
2 mutations causes freckling and red hair
What is the scientific name for freckles?
Ephilides
What do freckles represent?
Patchy increase in melanin pigmentation, usually due to UV exposure
What are actinic lentigines?
“Age/liver spots” caused by UV exposure
What is a naevus?
Birthmark/mole on the skin
Naevi can develop into melanoma.. True/False?
True
How do acquired naevi develop?
At infancy, melanocyte:keratinocyte ratio breaks down, allowing formation of simple benign naevi
Where are melanocytes in a junctional naevus?
At the DEJ
Where are melanocytes in a compound naevus?
DEJ + dermis
Where are melanocytes in a intradermal naevus?
Dermis
What size are dysplastic naevi?
Generally greater than 6mm
List the 4 main types of melanoma
Superficial spreading
Acral/mucosal lentiginous
Lentigo maligna
Nodular
How do superficial spreading, acral/mucosal lentiginous and lentigo maligna melanoma differ from nodular melanoma, in terms of growth?
SSM, A/MLM and LMM grow as flat lesions in epidermis before vertically invading; NM vertically grows from the outset
What is the most common subtype of melanoma? Where is it found?
Superficial spreading
Trunk or legs
Describe seborrhoeic keratosis
Greasy, stuck-on appearance common on face and trunk
Hyperkeratotic
