Skin Cancer Flashcards
What does ABCDE stand for in terms of skin cancer?
Asymmetry Border Colour Diameter Evolution
What is Breslow’s thickness?
Deepest point of tumour invasion from the granular layer
What are the 2 main subgroups of skin cancer and what is the main difference between the 2 groups?
Melanoma - arise from melanocytes in basal layer
Non-melanoma (BCC & SCC) - arise from keratinocytes
Describe the differences basal cell carcinomas and squamous cell carcinomas in terms of how common they are, speed of growth, appearance, spread and prognosis?
Incidence: BCC more common that SCC
Speed of growth: BCC - slow growing. SCC - fast growing
Appearance: BCC - pearly, translucent +/- central ulceration, painless. SCC - crusty wart that is painful and can bleed
Spread & prognosis: BCC - local invasion, good prognosis. SCC - can become metastatic (rare)
Name some precursor lesions for non-melanoma skin cancer?
Actinic keratoses
Bowens disease
What is Xeroderma Pigmentosum?
Genetic disorder that increases risk of skin cancer on sun exposed sites - decreased ability to repair DNA damaged by UV light
What is an oncogene?
Overactive form of a gene that positively regulates cell division - drives tumour formation when there are multiple oncogenes
What is a proto-oncogene?
Normal, not yet mutated form of an oncogene
What is p53?
A tumour suppressor
What are tumour suppressors and an example?
Genes that negatively regulate cell division and prevent the formation of tumours
p53
What are the different Fitzpatrick Skin Types?
Type I = always burns, never tans Type II = usually burns, can tan Type III = can burn, usually tans Type IV = Always tans, never burns Type V = brown skin Type VI = black skin
Which type of skin cancer is ALWAYS found on skin exposed sites?
SCC - sun exposure is a risk factor for the other types but can be found elsewhere
A mutation in PTCH1 (part of the hedgehog signalling pathway) is associated with what type of skin cancer?
Basal cell carcinoma
Mutations in Ras/Raf/MAPK signalling pathways are associated with what type of skin cancer?
Melanoma
What are freckles?
Patchy increase in melanin pigmentation
What are actinic lentigines?
Liver/age spots
Increased melanin and basal melanocytes due to chronic sun exposure (not-premalignant)
What are simple naevi?
moles - develop in childhood at the dermal-epidermal junction and migrate into the dermis by adulthood
What are dysplastic naevi?
clinically atypical moles - >6mm diameter and asymmetrical border
two types - sporadic and familial