Skin Cancer Flashcards
1
Q
what are the majority of skin cancers- melanoma or non melanoma
A
non melanoma- esp basal cell
2
Q
what do non melanoma skin cancers arise from
A
keratinocytes within the epidermis
3
Q
what do basal cell skin carcinomas arise from
A
keratinocytes within the basal layer of the epidermis
4
Q
where do squamous cell skin cancers arise form
A
suprabasal layer of the skin
5
Q
where are melanocytes
A
scattered along the basal layer of the epidermis
6
Q
what is the most serious form of melanoma
A
melanoma
7
Q
why are skin cancers becoming more common
A
cheap air travel, more leisure time, sun-seeking behaviour, ageing population
8
Q
what percentage of cancers in UK are skin
A
one third
9
Q
what facts show melanoma is so serious
A
only 6% of skin cancers but 75% of skin cancer deaths
10
Q
what is the most common cancer in 15-24 year olds
A
melanoma
11
Q
why are malignant melanomas more likely to metastasise than keratinocyte skin cancers
A
as melanocytes migrate into the skin from the neural crest and are motile cells that move around (unlike keratinocytes)
12
Q
what does melanoma survival depend on
A
tumour depth- breslow thickness
less than 1mm 5 year survival 95-100%
greater than 4mm 50%
13
Q
what is the ABCDE rule for malignant melanomas
A
Asymmetry Border Colour Diameter Evolution
14
Q
a diameter of more than what is a high risk melanoma
A
6/7mm
15
Q
how quickly will melanomas change
A
weeks and months
16
Q
what is the ugly duckling sign
A
a lesion that looks different to all the others
17
Q
why are moles important
A
genetic predisposition to getting skin cancer
18
Q
name 2 types of non melanoma skin cancer
A
basal cell carcinoma
squamous cell carcinoma
19
Q
describe basal cell carcinomas
A
slow growing lump or non healing ulcer (shiny lumps)
painless, often ignored
locally invasive, doesnt spread- treated with surgery
20
Q
describe squamous cell carcinomas
A
warty/ crusty lump/ ulcer
arises from sun damaged skin
grow slower than basal, may be painful or bleed
if neglected may spread
21
Q
name the cancer: pearly/ transulcent visible, arborising blood vessles central (rodent) ulceration locally invasive, rarely metastasise
A
basal cell carcinoma
22
Q
how else can basal cell carcinomas present
A
scaly plaque, superficial
nodular or nodulocystic
inflitrative ‘morphoeic’ (hard to see and define outline)
pigmented
23
Q
name the cancer hyperkeratotic (crusted) lump/ulcer arises on sun damaged skin grows relatively fast may be painful/bleed chance of metastasis low but poor prognosis if so
A
squamous cell carcinoma
24
Q
what are the prescursors of squamous cell carcinoma
A
actinic keratoses and bowens disease (carcinoma-in-situ)
25
what is keratoacanthoma
self resolving from of SCC
26
what are where are cutaneous horns
squamous cell carcinoma, on top of ear
27
where is a high risk site for squamous cell carcinoma
ear, lip and scalp
28
where do squamous cell carcinomas metasasise to
lymph nodes and bone
29
what is the 5y survival rate for metastatic SCC
25%
30
how else can SCC present
chronic ulcer, scars, wounds
31
what are actinic keratoses
pre cancerous skin lesions
32
what are actinic keratoses associated with
risk of developing SCC or BCC
33
what does multiple actinic keratoses suggest
a field of abnormality
34
what does bowens disease look like
erythematous plaque
35
what are the risk factors for skin cancer
sun exposure
genetic predisposition (white and ginger)
immunosuprpesion
enviromental carcinogens
36
give 6 examples of environmental carcinogens
coal tar, smoking, radiation, aresenic, trauma, chronic ulceration
37
name 4 genetic syndromes that predispose to skin cancer
DNA repair syndromes (xeroderma pigmentosum)
albinism
Gorlins syndrome
epidermolysis bullosa
38
what is xeroderma pigmentosum
a photosensitivity disorder die to defective nucleotide excision repair
causes photodamage and neurological degeneration
39
what is gorlins syndrome
autosomal dominant familial cancer syndrome
| early onset/ multiple BCCs
40
what defect do you get in recessive dystrophic epidermolysis bullosa
mitten defromities
41
what are causes of immunosupression (all immunosuppression leads in marked increase in skin cancers)
organ transplant treatments
haematological malignancies
immunosuppresant therapies for IBD, RA, vasculitis
HIV/AIDS
42
what is 'transplant hands'
field cancerisation on the hands of transplant patients
43
what is clonal evolution
when a series of mutations accumulate in successive generations
44
what does field cancerisation result in
many different mutations and possible tumours arising from one tumour
45
what are the 6 hallmarks of cancer
sustaining proliferation signalling
evading growth suppressors
activating invasion and metastases
enabling replicative immortality
inducing angiogenesis
resisting cell death
46
what are the two emerging hallmarks of cancer
deregulating cellular energetics
avoiding immune destruction
47
what are the enabling characteristics of cancer
tumour promoting inflammation
genome instability and mutation
48
what is an oncogene
over active form of a gene that positively regulates cell division- drives tumour formation
49
name two growth factors
RAS and RAF
50
what is a proto-oncogene
the normal, not yet mutated, form of an oncogene
51
what is a tumour suppressor
inactive or non functional form of a gene that negatively regulates cell division
52
name two tumour suppressors
Rb, TP53
53
what is a driver mutation
a mutation that drives the cancer e.g. increases mutation rate or prevents cell dying
54
what does RAS do
growth factors bind to growth factr receptors which then activates RAS causing cell division and proliferation
turned off when no growth factors circulating
55
describe oncogenic RAS
always activated- constantly initiating cell division and proliferation
56
what is the role P53
tumour suppressor
- binds to cell DNA
- cell halts at G1 checkpoint
- DNA repair activated
- apoptosis triggered
57
what happens if P53 is non functional
damaged DNA (mutations) are passed on
58
what type of melanin is in yellow skin and why does it increase skin cancer risk
pheomelanin- doesnt absorb UV radiation, cant tan as a protective response. Freckles sign of damage
59
what is the type of melanin in brown and black skin
eumelanin
60
what happens to keratinocytes when you sunburn
they die, sheet of skin is replaced
61
what type of UV exposure causes SCC
life long accumulative UV exposure
62
what type of UV exposure causes BCC and MM
intermittant burning episodes as usually on lesser exposed sites (BCC 40% on lesser exposed, 60% MM)
63
when does 80% of skin damage occur by
the age of 18
64
when do you get UVB and UVA expsoure in scotland
UVB only midday summer
| UVA daylight all year round
65
describe how UVB and UVA and different mutagen
UVB direct mutagen
| UVA indirect mutagen through oxidation
66
what wavelength of UV is filtered by window glass
UVB
67
can UV cause immunosuppression
yes
68
what is the UV signature DNA damage
pyrimidine dimer - covalent bonds formed between adjacent bases on same DNA strand (CPDs and 6-4 photproducts) causing C-T or CC-TT mutations
69
what usually removes CPDs and 6-4PP, how?
nucleotide excision repair
1. Recognition of the damaged DNA
2. Cleavage of the damaged DNA on either
side of the photoproduct
3. DNA polymerase fills in the gap, using
the undamaged strand as a template
4. DNA ligase seals the ends
70
UVA causes indirect DNA damage by oxidation of DNA bases. what usually repairs oxidised bases
base excision repair
71
what happens in oxidattive DNA damage
Oxidation of deoxyguanosine forming 8-oxo-deoxyguanosine
creates C to A point mutation
72
how does UV exposure cause immunosuppression
causes secretion of immunosuppressant cytokines (IL-10) from keratinocytes and dermal DC cells (macrophages)
Lanngerhans cells depleted and loose antigen presenting ability
CD4 T cells predominate
73
a mutation in what gene which is an important part of which signalling pathway is associated with BCC development
PTCH1
| Hedgehog
74
what mutations are important in melanomas
RAS, RAF, MAPK
75
what is the treatment for actinic keratosis
topical treatment- aldara (immunomodulator/ efudix- cytotoxic)
76
when do seborrheic keratosis develop and look lik
middle/ old
| stuck on, warty surface, well defined
77
what grows quicker BCC or SCC
SCC
78
acantholysis + positive immunofluorescence =?
bullous pemphigus
79
what are bowens and actinic keratosis precursors of
SCC
80
what is a splitz naevi
red, usually in childre/ young adults
| mostly benign
81
why is a blue naevus blue
as melanocytes deep in dermis
82
why are SCC scaly
have a lot of keratin
83
what is a nodule in MM suggestive of
vertical growth phase
84
what are dermatofibroma
very firm, common benign lesions
proliferation of dermal fibroblasts
common in middle aged/ older women, possible in response to trauma (insect bite)
85
what are features of basal cell PAPILLOMAS
well defined, unchanging (seb keratosis)
86
what is a halo naevi
depigmentation around the mole as immune system tries to get rid of it
87
what is haemangioma
benign proliferation of blood vessels in the skin
88
should all things removed from the skin be sent to pathology
YES
89
what are the indications for skin biopsy
skin rash- to help in diagnosis
tumours- assist in diagnosis, remove malignancy, remove unwanted skin growth
90
which cancer has a rolled edge
BCC
91
do you remove dermatofibroma
no- benign
92
how do you treat a MM
surgery
+ new therapies possibly
-photodynamic
- 5% imiquimod cream
further radiotherapy or chemotherapy may be needed
93
what is the treatment for common pre cancers
```
cryotherapy
solaraze
5 FU
PDT
imiquimod
resurfacing
```
94
what is an excision biopsy
when you remove the whole tumour
95
how does smoking affect surgery patients
causes decreased wound healing
96
what areas as are risky for skin surgery
tiger country (temples due to temporal artery)
eyelids, scalp, skin tension lines, in front of ear (facial nerve)
cosmetic effect- vermillion (lips), hairline
97
what are the 5 layers of the scalp
skin, connective tissue, aponeurosis, loose connective tissue
98
what facial nerves do shingles commonly affect
ophthalmic
maxillary
mandibular
(all from trigeminal nerve)
99
what are the methods of local anaesthesia
topical cream or subcutaneous infection (nerve of field block)
100
how does adrenaline help in surgery
prolongs anaesthesia and reduces bleeding
101
how do you reduce pain during local anaesthesia
relax patent, topical local, fine needle, warm local, massage skin, slow injection
102
what are the complications of skin biopsy
bleeding, wound dehiscence (wound break down), infection, scarring, motor or sensory nerve damage, loss of function
103
what is electrosurgery used for
haemostasis and minor skin lesions e.g. skin tags
104
what is a snip excision
cut across base of lesion with scissors as lesion grasped upwards with hook
105
what are the negatives of a punch biopsy
difficult to judge depth
| round holes do not often heal well pathology sample may be too small
106
what are the breslow prognostic parameters
<1mm good
1-4mm moderate
>4mm poor
107
what is a sentinel node biopsy
removal of the first lymph node that the tumour could spread to to asses metastasis
108
where does melanoma commonly spread to
skin, lung, bran and liver
