Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

PATH3309 > Melanoma > Flashcards

Melanoma Flashcards

1
Q

What is melanoma?

A

Tumor derived from melanocytes

Can arise in other organs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

How common is melanoma?

A

4th most common cancer in Australia
1/14 males
1/23

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is survival chance of 5 years if caught early?

A

96%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is % chance of 5 yr survival if local spread?

A

63%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is % chance of 5 yr survival if metastatic spread?

A

34%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are some risk factors for melanoma?

A

Strongest

  • Family hist
  • Large number of moles/birth marks (naevi)
  • Previous melanoma

Others

  • Immunosuppression
  • Sun sensitivity
  • Exposure to ultraviolet radiation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the model for the development of melanoma?

A 
Benign Nevus
Dysplastic Nevus
Radial-Growth Phase
Vertical - Growth Phase = Tumour
Metastatic Melanoma
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the characteristics of the Benign Naevus?

A

Clinically

  • Small
  • Well circumscribed
  • Even coloration

Histologically

  • Symmetrical
  • Cells predominantly in nests
  • Round to oval, even nuclei
  • “Maturation” as cells get deeper
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What type of Naevus are there?

A

Spitz Naevus - histo looks cancer, and found in chidlren

Blue Naevus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are Dysplastic Naevus?

A 
>6mm - larger than benign naevi
Irregular borders
Variable colouration
Can develop large numbers
 - Dysplastic naevus syndrome
Increased risk of developing melanoma
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the histological characteristics of Dysplastic Naevus?

A

Less symmetrical
More single cell growth
Some larger, darker nuclei
Fibrosis in upper dermis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the ABCDE’s of melanoma detection?

A 
A = Asymmetrical
B = Border Irregularity 
C = Color variability 
D = Diameter
           - > 6mm as a guide
E = Evolving
          - i.e. changing
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the microscopic features of Melanoma?

A 
Assymetrical
Poorly circumscribed
Single cells predominate over nests
Growth in continuity from one rete ridge to another
Extension into upper levels of epidermis
- Pagetoid spread
- "Buckshot" scatter

Cytological atypia

  • Nuclear enlargement
  • Hyperchromasia
  • Irregularity
  • Prominent nucleoli
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What does the Radial growth phase refer to?

A

Growth within the epidermis along with microinvasion into superficial dermis

Lacks metastatic potential

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What does the vertical growth phase refer to?

A

Invasive melanoma in the dermis
Mitotic figures
Large dermal nests
Capacity for metastatic spread

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are some prognostic indicators?

A

Men do worse than women
Old do worse than young
Back, upper arm, neck and scalp do worse than other sites

17
Q

What are some microscopic prognostics indicators of melanoma?

A

Tumour thickness
- Breslow thickness

Level of invasion
- Clark level

Ulceration
Mitotic rate
Lymphovascular or perineural invasion
Satellite lesions

18
Q

What types of melanoma are there?

A

Superficial spreading melanoma (buckshot pattern)

Nodular melanoma (Minimal epidermal component)

Lentigo Maligna Melanoma (Sun damaged skin, elderly)
- single cell growth pattern

Acral Lentiginous Melanoma

  • Acral sites, feet hands etc
  • Most common in dark skinned
19
Q

Can melanomas regress and is this good or bad?

A

Yes they can
Immune system destroys melanoma cells
Indicates worse prognosis
Can find metastatic melanoma but no primary tumour

20
Q

Do different chromasomal aberrations exist for different subtypes of melanoma?

A

Yes

21
Q

What chromosomal aberrations are more common in acral melanomas?

A

Amplifications

Copy number increases in regions of cyclin D1, CDK4 and PDGFR

22
Q

What gene is commonly mutated in melanoma?

A 
BRAF V600E (glutamate - valine)
66% of melanomas
Point mutations
Kinase domain
23
Q

What happens due to BRAF mutation?

A

Activation of kinase activity

24
Q

Are BRAF mutations common in naevi?

A

yes

25
Q

Are other mutations needed for development of melanoma other than BRAF?

A

Yes

26
Q

Are there drugs that target V600E positive cells?

A

Yes

27
Q

On what what body part do BRAF mutant melanomas arise on?

A

Trunk, intermittently rather than chronically exposed to sun

28
Q

What histo features do BRAF mutant melanomas exhibit?

A

Upward scatter of intraepidermal cells
Nested Pattern
Heavy pigmentation

29
Q

How often are NRAS mutations found in melanomas?

A

15%

HRAS + KRAS rare

30
Q

In what kind of melanomas are KIT mutations found?

A

Glabrous skin (skin with no hair)
Nail
Mucosa
Skin with chronic sun exposure

31
Q

Is BRAF mutation common in KIT mutations?

A

No relatively uncommon

32
Q

What features do KIT mutations express?

A

Increasing incidence with age
Lentiginous growth pattern
Poorly circumscribed margins

33
Q

Overall what kind of mutations are associated with melanoma?

A

BRAF mutations
NRAS
KIT
G protein mutations

34
Q

What does G protein mutation lead to?

A

Constitutive activation

35
Q

In what melanomas have G-protein mutations been found in?

A

Blue Naevis

Uveal melanomas

36
Q

What is the divergent pathway hypothesis for melanoma?

A

Those with tendency to develop lots of naevi may initiate melanoma after only modest sun exposure
Those with less tendency for naevi development require repeated exposure

37
Q

What are the two emerging subtypes of melanoma?

A

Chronic sun damage melanomas

  • Arise after 5th decade
  • Lentiginous, mutations in KIT, NRAS, BRAF less common

Non-chronic sun damage melanomas

  • Peaks 5th decade
  • Intermittently exposed sites
  • Associated with naeivi
  • Nested growth
  • High frequency BRAf

Melanomas arising from epithelial melanocytes
- Acral melanomas
- Uv not causative
Unusual degree of genomic instability

Melanomas arising from non-epithelial melanocytes

  • Intradermal - blue naevi
  • Uveal melanomas
  • G-protein mutations

PATH3309 (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions