Skin Cancer Flashcards

1
Q

skin is made up of what 3 layers?

A
  • epidermis
  • dermis
  • hypodermis
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2
Q

what are the 4 layers of epidermis?

A
  • stratum cornea
  • stratum lucidum
  • stratum spinous
  • stratum basale
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3
Q

What are the 4 major types of skin cancer?

A
  • Keratinocyte derived
    eg basal cell carcinoma, squamous cell carcinoma
    aka Non melanoma skin cancer (NMSC)
  • Melanocyte derived
    eg Malignant melanoma
  • Vasculature derived
    eg Kaposi’s sarcoma, angiosarcoma
  • Lymphocyte derived
    eg Mycosis fungoides
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4
Q

skin cancer arises due to accumulation of genetic _____ –> which causes it to ______ in a uncontrolled manner

A

skin cancer arises due to accumulation of genetic mutation –> which causes it to proliferate in an uncontrolled manner

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5
Q

What are some causes of skin cancer?

give examples of each cancer derived from each cause/.

A
  • Genetic syndromes
    Gorlin’s syndrome
    xeroderma pigmentosum
  • Viral infections
    HHV8 in Kaposi’s sarcoma
    HPV in SCC
  • UV light (most common cause)
    BCC, SCC, malignant melanoma
  • Immunosuppression
    drugs, HIV, old age, - leukaemia
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6
Q

Malignant melanoma = tends to be of higher prevalence in white ethnicity individuals

A

-

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7
Q

Basal cell carcinoma = increasing in incidence

what are they caused by?

A

sun exposure

Genetics

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8
Q

UVA –>has higher penetration
- major cause of skin aging
contributes to skin carcinogenesis

A

-

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9
Q

How doe UVB induce DNA Abnormalities of the skin?

A
  • UVB directly induces abnormalities in SNA
  • -> induces photoproducts
  • -> affects pyramiding Cytosine + thymine ases

–> usually repaired quickly by nucleotide excision repair

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10
Q

What things can UV damage induce to DNA?

A
  • cell division
  • dna repair
  • cell cycle arrest defect.
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11
Q

What mutations can cause skin cancer?

A
  1. Mutations that stimulate uncontrolled cell proliferation
    Eg abolishing control of the normal cell cycle (p53 gene)

2/ Mutations that alter responses to growth stimulating / repressing factors

3.Mutations that inhibit programmed cell death (apoptosis)

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12
Q

what is sub burn?

A

Exposure to UV –> build up of mutations –> apoptosis of the keratinocyte occurs –> protects cells from becoming cancer cells.

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13
Q

UVA and UVB effect the expression of genes involved in skin immunity
–> Depletes / increases Langerhans cells in the epidermis

A

UVA and UVB effect the expression of genes involved in skin immunity
–> Depletes / increases Langerhans cells in the epidermis

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14
Q

in exposure to UV, there will be a reduced immunocompetence + immunosurveillance

A

-

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15
Q

melanin is produced by

A

melanocytes within the basal layer of the epidermis

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16
Q

skin color depends on:

A

the amount and type of melanin produced

17
Q

What are the 2 types of melanin formed?

A

Eumelanin – brown or black
Phaeomelanin – yellowish or reddish brown

—> Melanin is formed from tryosine via a series of enzymes

18
Q

regulation of melanin type production is controlled by

A

MCR1 gene

19
Q

define malignant melanoma

caused by:

A

Malignant tumour of melanocytes

  • -> Melanocytes become abnormal
  • -> Atypical cells and architecture

caused by:
UV exposure
Genetic factors

20
Q

what is lentigo maligna

A

(Melanoma in situ)

  • Proliferation of malignant melanocytes within the epidermis
  • No risk of metastasis
  • light / dark brown colors
  • irregular shape
21
Q

what is lentigo maligna melanoma

A
  • there is superficial spreading MM
  • Lateral proliferation of malignant melanocytes
  • Invade basement membrane
  • Risk of metastasis
22
Q

How would you diagnose superficial spreading malignant melanoma?

A

ABCD rule

  • Asymmetry
  • Border irregular
  • Colour variation (dark brown-black)
  • Diameter >0.7mm and increasing
  • Erythema
23
Q

what is nodular malignant melanoma?

A
  • grows downwards
  • bad prognosis
  • Vertical proliferation of malignant melanocytes
  • risk of metastasis

–> sometimes accompanies with spreading melanoma as well

24
Q

What is Acral lentiginous melanoma

A
  • melanoma of palms / soles
25
Q

what is Amelanotic melanoma

A
  • no production of melanin at all

- often difficult to diagnose

26
Q

What re the 5 main types of malignant melanoma?

A
Superficial spreading
Nodular
Lentigo maligna melanoma
Acral lentiginous
Amelanotic
27
Q

How is melanoma prognosis determined

A
  • breslow thickness

- measurement from granular layer to bottom of the tumour

28
Q

What are main risk factors for the development of melanoma?

A
  • family history
  • UV radiation
  • sunburns during childhood
  • skin type I + II
  • personal history of melanoma
  • atypical/ dysplastic nevus syndrome
29
Q

What is squamous cell carcinoma usually caused by?

A
Caused by 
	UV exposure
	HPV
	Immunosuppression
	May occur in scars or scarring processes
30
Q

Is there risk of metastasis in Squamous cell carcinoma?

A
  • yes
31
Q

What is SCC ?

A

Malignant tumour of keratinocytes

- may commonly occur on lips/ ears (high risk)

32
Q

What is basal cell carcinoma?

A

Malignant tumour arising from basal layer of epidermis

  • slow growing
  • invades tissue but doesn’t metastasis
  • common on face
  • commonly arborising (like tree branches) telangiectasia
33
Q

what is Epidermodysplasia veruciformis?

A

(tree man)
Rare autosomal recessive condition
–> predisposition to HPV
–> induced warts and SCCs

34
Q

What is Kaposi’s sarcoma

A

tumor of endothelial cells of the lymphatics

  • purple nodules on skin
  • associated with HIV / HHV8
35
Q

what is the main treatment for these skin cancers ?

A
  • surgical