Flashcards in Photocarcinogenesis Deck (52):
1
Bullous impetigo
(blistering at site of infection)
Caused by staphylococcus toxin A
2
Staphylococcal scalded skin syndrome
Caused by staphylococcus toxin B
Most common in children
Low mortality rates
3
Organism usually causing cellulitis
Beta haemolytic strep
4
Another name for basal cell papilloma
Seborrhoeic wart
5
Appear as firm, elevated pigmented nodules which may feel like a button in the skin
They are often found on the legs and commoner in females
There may be a history of trauma or insect bite
Dermatofibroma
6
Keratoacanthoma
Rapidly growing epidermal tumours which develop central necrosis and ulceration
They occur on sun exposed sites and can grow to 2-3cm across
Whilst they may resolve spontaneously, best to surgicaly remove as they can mimic squamous cell carcinoma
7
Where does Bowen's disease most commonly develop?
Lower womens legs
8
Where would you usually develop a pilar cyst?
The scalp
9
Key characteristics or "hallmarks" of cancer
1. Insensitivity to growth signals
2. Insensitivity to anti-growth signals
3. Evade death (apoptosis)
4. Limitless potential to divide
5. Angiogenesis
6. Invasion and metastasis
10
Basal cell carcinoma and exposure
Intermittent exposure
11
Squamous cell carcinoma and exposure
Chronic exposure
12
Melanoma and exposure
Intermittent exposure
13
Lattitude and skin cancer
Incidence increases closer to equator
14
Skin colour and eye colour and cancer
Red/fair haired individuals with blue eyes and freckling
15
Where would patients with Xeroderma pigmentosum (XP) develop skin cancer?
Skin exposed areas
16
UVC wavelength
200-280 nm
17
UVB wavelength
280-315 nm
18
UVA wavelength
315-400 nm
19
Visible light spectrum
400-700 nm
20
UV signature mutation
Cytosine to thymine (at dipyrimidine sites)
21
NER
Nucleotide excision repair
22
BER
Base excision repair
23
DSB
Double strand break repair
24
MMR
Mismatch repair
25
Which UV is mainly responsible for initiating mutations?
UVB
26
Which UVs are responsible for promoting mutations etc
UVB/UVA
27
Estiamted action spectrum for cancer in humans?
298nm
28
Age onset of MM?
<20 years
29
Merkel cell skin cancer exposure
?cumulative
30
HPV associated with which types of skin cancer?
BCC and SCC
31
Metastases common in which type of cancers?
MM and MCC
(malignant melanoma and merkel cell carcinoma)
32
Most common site for BCC?
Face and 1/3 sun protected sites
33
Main site for SCC?
Sun exposed sited
34
Main sites for malignant melanom?
Face, legs, back
35
Main site for MCC?
Head/neck, sun exposed sited
36
BCC formed from which type of cell?
Keratinocytes
37
Major risk factor for BCC?
Immunosuppression (x10)
This is even BIGGER risk factor in SCC (65-250x)
38
Eating this poison can increase risk of BCC?
Aresenic
-same for SCC
39
Syndromes predisposing to BCC?
XP
Basal cell nevus syndrome (Gorlin syndrome)
40
BCC risk factors
Intermittent sun exposure/sunburn Immunosuppression (10x)
Ionizing radiation
Arsenic ingestion
?photosensitising drugs Family/personal history of BCC/SCC
41
SCC precursor lesions
Actinic keratoses
Bowen's disease
42
Risk factors for SCC?
Chronic/cumulative sun exposure. Sunbeds.
Immunosuppression (65-250x)
Arsenic /petroleum products/organophosphates/smoking/scars/HPV ?photosensitising drugs
Family/personal history of BCC/SCC
43
SCC predisposing syndromes
XP
Rothmund Thomson syndrome
Bloom syndrome
Werner syndrome
Dystrophic epidermolysis bullosa
Fanconi anaemia
44
Precursor lesions for melanoma
Moles
45
Where are melanomas usually found?
Chest/back (men)
Legs (women)
Palms and soles
Growing under the nails
Eyes
46
Risk factors for melanoma
Risk factors:
Intermittent sun exposure/sunburn. Sunbeds
Ionizing radiation
Immunosuppression
?photosensitising drugs/?heavy metals/?other occupational exposure Family/personal history of CM/BCC/SCC
47
Melanoma predisposing syndromes
XP
Atypical mole syndrome
48
Drugs associated with photocarcinogenesis
Psoralen
Voriconazole
Azathioprine
Vemurafenib
Photosensitising drugs
Immunosuppressants
Topical
49
UV and langerhans cells
UV reduced number of langerhans cells
50
UV and oxidative stress
Increases oxidative stress
51
UV and exogenous compounds
UV interacts with exogenous compounds
52