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Dermatology Diploma > Dermoscopy > Flashcards

Flashcards in Dermoscopy Deck (51)
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1

Describe how the description of local features varies from global features with regards to dermoscopy?

  • Pigment network vs Reticular pattern
  • Dots and Globules vs Globular Pattern
  • Streaks/Pseudopods vs Starburst Pattern
  • Blotches vs Homogenous Pattern
  • Regression vs Multicomponent

There is also a Non-Specific pattern naevus.

(Local features various aspects of the naevus whereas the global features describe the overall impression)

2

Describe the colour changes that are seen in dermoscopy?

3

How does pigment network vary from typical to atypical naevi?

What lesions is it seen in?

Typical naevi have a regular uniform pattern.

Ayptical naevi are non-uniform, with heterogenous holes & end abruptly.

  • Aquired melanocytic naevi
  • Thin malignant melanomas.

4

How do globular patterns of pigmented lesions change between naevi and atypical naevi/malignant melanoma?

What lesions have globular patterns?

central = naevi

peripheral = malignant melanoma/Atypical

 

  • Melanocytic naevi = especially compound and intradermal naevi
  • Cobblestone effects is a form of globular pattern and is seen in larger lesions:
    • Congenital melanocytic naevi
    • Seborrheic Keratoses

5

Describe how the starburst pattern (global) or streaks/peudopods (local) vary between typical and atypical lesions?

What lesions are these often seen in?

Symmetical peripheral arrangement = benign naevi & Spitz/Reed's naevi

Irregular and patchy = malignant melanoma

6

Describe how a homogenous pattern (global) or blotches (local) change between typical naevi and ayptical naevi/malignant melanoma?

Central blotch/homogenous colour = typical naevus

Irregular or peripheral placed blotches = melanoma

7

In what 2 lesions is a blue/white veil seen?

Melanoma and Spitz/Reed Naevi

8

What pattern is this?

Multicomponent Pattern

(There are 3 or more components)

It is highly suggestive of melanoma

9

What pattern is this and how is it managed?

Non-specific pattern

Always consider a malignant melanoma.

10

What pattern is this?

Where is it seen?

How do you know when it is melanom?

Parallel Pattern

Seen acrally

Parralel Ridge Pattern is seen in melanoma - it is thicker and has eccrine gland openings on it.

Parralel Furrow Pattern is seen in typical naevi.

(Ridge is wrong)

11

What type of naevi is this?

Junctional melanocytic naevi

12

How do aquired melanocytic naevi change with age?

  • In children and teenagers - there is a peripheral rim of brown globules as a sign of growth. (Pseudopods)
  • Regular reticular and homogenous pattern in 30s+.
  • Regress with age.
  • Disappear in 70s and above.

13

What type of naevus is this?

Compound melanocytic naevus

(Usually have a raised central portion with a typical globular pattern)

14

What type of naevus is this?

What are its typical dermoscopic features?

Intradermal melanocytic naevi

  • Globular pattern
  • Comma-like blood vessels
  • Cobblestone pattern

15

What is this?

What can happen to the central part?

Blue Naevus

The central part can undergo focal fibrosis. (aka Sclerosing blue naevi)

16

What is this?

Reed Naevus

Seen in adults - legs of females.

It has a starburst pattern.

17

What is this?

Spitz Naevus

  • More commmon in children
  • Amelanocytic version of the Reed naevus.

18

What type of naevi are these?

Atypical Naevi (aka Clark's naevi)

 (Containing similar patterns to melanoma)

NOTE: Establish the predominant pattern of the individual or if they have many atypical naevi on examination.

19

What percentage of melanoma come from aquired naevi?

Describe how you can tell if a melanoma might be growing from a naevus on dermoscopy?

50%

  • Look for the dermoscopic island - a well circumscribed area of uniform dermoscopic pattern that differs from the rest of the lesion - this is most likely the melanoma

20

Describe the 3 Point Checklist

  • Assymmetry of colours and structures
  • Atypical or irregular pigment network
  • Blue-White Veil

A score of 2 out of 3 means that a biopsy needs to be performed.

21

What are the 10 most common dermoscopic features of malignant melanoma?

  1. ​Atypical pigment network
  2. Negative (inverse) pigment network
  3. Focal Streaks (pseudopods/radial streamin
  4. Eccentric blotch
  5. Atypical dots/globules
  6. Blue-white veil
  7. Crystalline (chrysalis) structures
  8. Regression structures
  9. Atypical vascular structures (Polymorphous vessels)
  10. Multiple colours

22

Analyse this melanoma using the 3 point checklist

  • Assymetrical colours and structures
  • Atypical pigment network
  • No blue with veil

THEREFORE

2/3

23

Analyse this melanoma using the 3 point checklist

  • Asymmetrical colours and structures (blotches, atypical streaks, peripheral globules)
  • Atypical pigment network
  • Possible blue-grey veil

This is a multicomponent pattern

3/3

24

Describe this using the 3 Point Checklist

  • Normal colour and structure
  • Irregular pigment network
  • Blue-Grey Veil

2/3

25

Dermoscopically, how can you determine if hypopigmented or amelanotic lesion is a melanoma?

  • Looks like a BCC/SCC
  • Foci of pigment remnants - look for blue or gray areas.
  • Atypical vascular pattern - presence of polymorphous blood vessels (dotted, hairpin and irregular linear vessels.)
  • More than one shade of pink.
  • White shiny lines - only seen on polarised dermatoscopes.

26

What percentage of nodular melanomas are invasive melanomas?

10-15%

27

How do nodular melanomas present?

Rapidly growing papules or nodules that ulcerate or bleed.

28

Why are nodular melanomas difficult to diagnose at an early stage on dermatoscope?

The normal features of a superficial spreading malignant melanoma are lacking.

29

What are the typical dermoscopic features of a nodular melanoma?

  • Blue gray structures
  • White polarized lines (chrystalline structures).
  • Irregularity of colour
  • Atypical vascular pattern

30

How are the "rete ridges"on the face different?

How does this affected dermoscopy of pigmented lesions?

Rete Ridges are flat on the face and thus a "pseudonetwork" = a broad mesh with wider holes.

 

The pseudonetwork does not distinguish between melanocytic and non-melanocytic lesions