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Dermatology Diploma > Pigmented Lesions > Flashcards

Flashcards in Pigmented Lesions Deck (45)
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1
Q

What percentage of the cells in the basal layer are melanocytes?

A

5-10%

2
Q

Describe how melanocytes form

A
  • Epidermal melanocytes originate in the neural crest
  • As a foetus, the melanocyte migrates from the neural crest to the dermo-epidermal junction.
  • They reside as a single cells in the basal layer.
3
Q

How is skin colour controlled?

A

Dark skinned individuals do not have more melanocytes.

They have more melanosomes.

Melanosomes are secreted by melanocytes into surrounding keratinocytes.

4
Q

At what stage of life do the number of moles sharply increase?

A

Puberty

5
Q

What is a junctional melanocytic naevus?

A

A mole that is confined to the dermoepidermal junction

6
Q

Over time, naevus cells can extend into the dermis.

What is this called?

A

A compound naevus

7
Q

Over more time, melanocytic cells can migrate fully into the dermis.

What is this called?

A

Intradermal naevus.

(All the junctional components have been lost)

8
Q

What is this?

A

An intradermal naevus

  • No pigment
  • Papillomatousnodules.
9
Q

Is this a Junctional Naevus or a Compound Naevus?

A

Compound Naevus

  • Usually raised.
  • Colours vary
  • Sometimes hyperkeratotic
10
Q

What is a CMN?

A

Congenital Melanocytic naevi

(Think Birthmark)

11
Q

How are congenital naevi classified?

(According to size)

A
  • small CMN = <1.5 cm diameter
  • medium CMN = 1.5 - 19.9 cm diameter
  • large or giant CMN = 20 cm or more in diameter
12
Q

Why do Giant Congenital Melanocytic Naevi need to be monitored?

A

They have a 30% chance of malignancy

13
Q

What are the other benign naevi to be aware of apart from CMN?

A
  • Spitz naevus
  • Halo naevus
  • Becker’s naevus
  • Blue Naevus
14
Q

What is this?

When & Where does it occur?

How do you treat it?

A

Spitz Naevus

  • It usually grows rapidly on the face of a child
  • Reaches 1-2 cm and then stops.
  • AKA Juvenile Melanoma - but is benign
  • Best to excise as it is difficultto differentiate from a melanoma
15
Q

What is this?

A

Halo Naevi

  • Occurs on the trunk of children or adolescents
  • The body’s immune system is destroying the naevus cells.
16
Q

What is this?

A

Becker’s naevus

  • Becomes darker and hairy after puberty
  • More common in adolescent males
  • No effective treatment
17
Q

What benign naevus is this?

A

A Blue Naevus

  • Deep dermal collection of melanocytes.
  • As they migrate from the neural crest to the epidermis during foetal life they stop in the dermis rather than the dermalepidermal junction
  • Usually occur on the scalp, face, hands and feet.
18
Q

What are the characteristics of an atypical mole?

A
  • >5mm
  • Irregular shape
  • Smudged border
  • Irregular pigmentation +/- erythema
  • Papular + Macular component.
19
Q

What % of the population have Atypical Mole Syndrome?

What is their risk of developing melanoma?

A

1-5% of the population

10x risk of melanoma

20
Q

What is FAMM syndrome?

A

Familial Atypical Multiple Mole-Melanoma Syndrome

  • Mutation in the CDKN2A or CDK4 gene
  • Associated with pancreatic cancer.
  • 400x increase in melanoma risk if 1st and 2nd degree relatives have atpyical naevi + melanomas.
21
Q

What % of melanomas arise melanocytic naevi?

A

30%

22
Q

What factors lead to an increased risk of melanoma?

A
  • Sun exposure
  • Skin type
  • Large numbers ofmelanocytic naevi
  • Large CNS
  • Family history
  • Personal history
  • Immunosuppresion.
23
Q

Describe the cellular pathway whereby melanomas form?

A

40-60% of melanomas result from a BRAF mutation.

This leads to MEK & ERK phosphorylationand cell proliferation.

This is independent of extracellular growth factors.

24
Q

Describe the ABCDE Rule

A
  • Asymmetry
  • Border irregularity
  • Colour irregular/variable pigmentation
  • Diameter >6 mm (not always helpful)
  • Elevation / Enlargement / Evolution– any mole which clearly changes over weeks to months
25
Q

What is this?

A

Superficial spreading malignant melanoma

  • Most common melanoma
  • 80% of primary melanomas
  • Excellent prognosis (They are usually <1mm thick)
26
Q

What type of melanoma is this?

A

Nodular Melanoma

  • 10% of all melanomas
  • Worse prognosis due to vertical growth face from the beginning.
  • More common in males
  • More common on the trunk
  • Differential includes a vascular lesion.
27
Q

What type of melanoma is this?

A

Lentigo Maligna Melanoma

  • 10% of cases
  • Large irregular freckle
  • Solar lentigo is benign but lentigo maligna is cancer in situ.
  • Lentigo maligna melanoma can grow out of a lentigo maligna - invasive nodule develops with vertical growth phase.
28
Q

What is the most common form of melanoma in dark skin types?

A

Acral Melanoma

29
Q

What is Hutchinson’s Sign?

A

It is pigmentation that involves the nail bed.

A positive sign of acral melanoma.

30
Q

What type of melanoma is this?

A

Amelanotic melanoma

31
Q

What is the most important prognostic factor melanomas?

A

Tumour thickness (aka Depth)

Breslow Thickness

32
Q

Describe the Breslow Thicknes Stages

A
33
Q

Describe the Breslow thickness survival rates

A
34
Q

What Wide Local Excision Margins are recommended by the British Association of Dermatologists?

A

In situ: 5 mm

<1 mm: 1 cm

1.1 - 2 mm: 1-2 cm*

2.1 - 4 mm: 2-3 cm*

>4 mm: 3 cm

* Depends on anatomical site

35
Q

When should the sentinel lymph node be biopsied in melanoma?

A

If the thickness is greater than or equal to 1mm

36
Q

Is Sentinel Lymph Node Biopsy diagnostic or therapeutic?

A

Diagnostic

It is primarily a staging procedure - however, patients will go on to have a complete lymph node dissection.

37
Q

How are unresectable or metastatic melanomas managed?

A
  • BRAF inhibitors -Vemurafenib and Debrefenib
    • Only used in patients who have the V600E mutation.
  • MEK inhibitors - Trametinib
  • Immunotherapy
    • ​CTLA-4 Inhibitors - Ipilimumab
    • PD-1 Inhibitors -Pembrolizumab orNivolumab
38
Q

How should patients with stage 1A Melanoma be followed up?

A

3-4 monthly for 1 year and then discharged.

39
Q

How should patients with melanoma in situ be followed up?

A

No Follow Up Needed

40
Q

How should patients with Stage 1B to IIIA be followed up?

A

3-4 monthly for the first 3 years

then

Twice yearly for another 2 years

41
Q

How should patients with Stage IIIB and Above melanoma be followed up?

A

Every 3-4 months for the first 3 years

then

Twice yearly to 5 years

then

Annually to 10 years.

42
Q

What is the role of PET-CT scans?

A

Offered to patients suffering from Stage IIC and above

Offer at baseline

then

6 monthly for 3 years

then

Annually for 5 years.

43
Q

What blood test should be checked with melanoma patients?

A

Vitamin D

(Patients are advised to avoid the sun)

44
Q

What are some features of melanoma on dermatoscopy?

A
  • Asymmetry of pigment network
  • Asymmetry of lesion
  • Blue- white veil
  • Black dots and globules
  • Pseudopods
  • Asymmetrical vessels
  • Areas of regression
45
Q

How should suspicious solar lentigo be biopsied?

(Suspecting lentigo maligna)

A

Take an ellipse excision from the most abnormal looking section