skin cancer Flashcards Preview

cancer > skin cancer > Flashcards

Flashcards in skin cancer Deck (33)
Loading flashcards...
1
Q

DIAGRAM microanatomy of skin

A

epidermis, dermis, and hypodermis

2
Q

DIAGRAM structure of epidermis+ cells involved in cancer

A

stratum corneum, lucidum, spinosum and basale- keratinocytes are in all layers and are shed in corneum, melanocytes are present in basala

3
Q

types of skin cancer with examples

A

keratinocyte derived eg basal cell/squamous cell carcinoma- melanocyte derived eg malignant melanoma- vasculature derive eg kaposi’s/angiosarcoma- lymphocyte derived eg mycosis fungoides

4
Q

causes of skin cancer

A

genetic syndromes eg gorlins syndrome/xeroderma pigmentosum, viral infections eg herpes for kaposis, HPV in SCC, UV LIGHT (BCC, SCC, melanoma), and immunsurpression (eg HIV)

5
Q

who does malignant melanoma affect

A

has increased in WHITE ppl, not in other ppl

6
Q

which part of UK is melanoma most present

A

south of england (ie most sunlight)

7
Q

what types of UV radiation cause skin cancer

A

UVB and UVA, NOT UVC (blocked)- UVB most carcinogenic, but UVA penetrates deeper

8
Q

what mutation does UVb and a radiation cause

A

b produces photoproducts called thymine dimers, a does as well, but also free radicals

9
Q

bodys response to thymine dimers

A

removed by NUCLEOTIDE EXCISION REPAIR

10
Q

what is the defect in xeroderma pigmentosum

A

defective nucleotide excision repair

11
Q

what occurs in sunburn

A

UV causes keratinocyte cell apoptosis (otherwise may become cancer cells)

12
Q

difference in appearance between melanoma vs BCC

A

black vs pinkish in colour

13
Q

pathophysiology of skin cancer by UV

A

UV causes DNA damage, and if there’s a p53 mutation, leads to skin cancer- UV cells deplete langerhan cells (APCs) too in epidermis= further risk

14
Q

immune effects of UV light+ clinical signficance

A

depletes langerhan cells raises risk of skin cancer, BUT good for inflammatory conditions like psoriasi

15
Q

phototypes of skin+ significance

A

6 phototypes, from always burns never tans (ie white, most likely to get melanoma), to more likely to tan (brown), to afrocarribbean (never burn)

16
Q

melanin-what produced by, and what skin colour depends on

A

produces colour, produced by melanocytes- colour depends on amount of melanin, NOT amount of melanocytes ie afrocarribeans produce more melanin

17
Q

protective effect of melanin

A

keratinocytes produce MSH- melanocytes produce melanin, and keratinocytes place it around their nuclei to protect them, called MELANOSOMES- leads to tanning

18
Q

types of melanin and gene controlling it

A

eumelanin (brown/black) or phaeomelanin (red-brown)- determined by mutations in MCR1 gene

19
Q

what a.a is melanin derived from

A

tyrosine

20
Q

lentigo maligna ie in situ and appearance

A

malignant melanocytes proliferate in epidermis (should be in basale)- but NO RISK of metastasis- FLAT and DARK PATCH

21
Q

DIAGRAM superficial spread malignant melanoma- difference from lentigo maligna

A

melanocytes proliferate not just in epidermis, but downwards ie invade basement membrane= risk of metastasis- also LATERAL spread

22
Q

DIAGRAM nodular malignant melanoma

A

DOWNWARDS proliferation of melanocytes= metastasis

23
Q

nodular and superficial spreading

A

both- downwards proliferation with lateral spreading as well

24
Q

acral lentiginous melanoma- location

A

occur in palms or soles of feet

25
Q

amelanotic melanoma

A

non-pigmented

26
Q

diagnosing melanoma

A

ABCD- asymmetry, irregular BORDER, black COLOUR, above 0.7mm DIAMETER

27
Q

determining prognosis of melanoma

A

BRESLOW thickness- ie how deep from epidermis to bottom of tumour

28
Q

risk factors for melanoma

A

skin type 1/11, family history of melanoma

29
Q

keratoacanthoma- key feature and metastasis?

A

type of SCC of KERATINOCYTES- often have a white keratin HORN- risk of metastasis

30
Q

BCC- metastasis? where most common

A

arises from stratum BASALE (unlike SCC)- no metastasis, mostly on face

31
Q

mycosis fungoides

A

lymphoma of skin- looks like psoriasis

32
Q

kaposis sarcoma- cause

A

tumour coming from endothelial cells of lymph vessels- associated with herpes (HHP8) and HIV

33
Q

epidermodysplasia veruciformis+ cause

A

warts caused by HPV