Melanoma

Question 1

where do melanomas arise from

Answer 1

melanocytes

Question 2

where are melanocytes found in the skin

Answer 2

scattered along the basal layer of the epidermis

Question 3

why is melanoma the most serious form of skin cancer

Answer 3

• metastasis can occur early - number of deaths even in young people

Question 4

risk factors

Answer 4

• Pale skin
• Previous invasive melanoma or melanoma in situ
• Increasing age
• Previous BCC or SCC
• Multiple melanocytic naevi
• Sun sensitivity
• Immunosuppression
• Atypical mole syndrome
• Lentigo maligna

Question 5

outline the 3 phases of melanoma growth

Answer 5

• in situ - tumour is confined to the epidermis
• invasive - tumour has spread to the dermis
  
  • they may now spread via lymphatics or blood stream
• metastatic - has spread to other tissues

Question 6

how may tumours spread in situ

Answer 6

may spread out within the epidermis - the horizontal growth phase

Question 7

what does melanoma survival depend on

Answer 7

Breslow depth - the deepest tumour from the granular layer in mm

Question 8

Breslow depth prognostic values

Answer 8

• pTis-melanoma is in-situ-100% survival
• pT1-tumour < 1mm-90% survival (still in epidermis?)
• pT2-tumour is 1-2mm-80% survival
• pT3-tumour is 2-4mm-55% survival
• pT4-tumour > 4mm thick-20% survival

Question 9

what sign is used to identify melanomas

Answer 9

ugly duckling sign

Question 10

ABCDE rules

Answer 10

Asymmetry, Border, Colour, Diameter (>6mm), Evolution.

Question 11

why are nodular melanomas so bad

Answer 11

they have a vertical growth phase

Question 12

how does melanoma appearance change in horizontal and vertical growth phase

Answer 12

Melanoma is normally flat during the horizontal growth phase and becomes thickened and raised during the vertical phase

Question 13

which types of melanoma are associated with horizontal and vertical growth phases

Answer 13

• Horizontal growth phase: SSM, lentigo maligna melanoma and acrallentignous melanoma.*
• Vertical growth phase: nodular, spitzoid, mucosal*

Question 14

what is the most common type of horizontal melanoma

Answer 14

superficial spreading melanoma

Question 15

presentation of SSM

Answer 15

• slowly enlarging flat area of discoloured skin
• irregular shape

Question 16

outline the course of SSM

Answer 16

• malignant cells remain in situ for a longer period of time - months to decades
• have a primary horizontal (radial) growth phase
• some can become invasive, a nodular melanoma can arise within one

Question 17

how may deep and invasive SSM present

Answer 17

they may itch , sting or blled

Question 18

Acral/Mucosal Lentiginous Melanoma

Answer 18

• characterised by their site of origin: palms of hands, soles of feet or subungually
• relatively rare in comparison to other types

Question 19

who are Acral/Mucosal Lentiginous Melanoma more common in

Answer 19

people with darker skins

Question 20

are Acral/Mucosal Lentiginous Melanoma related to sun exposure

Answer 20

they may not be

Question 21

course of Acral/Mucosal Lentiginous Melanoma

Answer 21

• remain in situ for years, non invasive
• nodular melanoma can arise within them

Question 22

appearance of Acral/Mucosal Lentiginous Melanoma

Answer 22

• Start off with a smooth surface, which later may become thicker with an irregular dry/warty surface
• May ulcerate or bleed

Question 23

what is lentigo maligna melanoma related to, hence who and where is it seen

Answer 23

• sun exposure
• seen on sun damaged face/neck/scalp in older people
• risk relates to sun damage, more common in outdoor workers, solar damage, older people and keratinocyte skin damage (e.g. BCC, SCC)

Question 24

what is the precursor to lentigo maligna melanoma

Answer 24

• lentigo maligna - Hutchison’s freckle
• this is where a large facial mole undergoes central melanomatous change, the cells are still confined to the epidermis - in situ

Question 25

how does lentigo maligna present

Answer 25

* slow growing macular area of pigmentation seen in elderly people, commonly on the face

Question 26

what is the risk of developing invasive malignant melanoma from lentigo maligna

Answer 26

* slightly increase risk, increasing with larger lesions * but there is a lower risk than there is with other forms of melanoma in situ

Question 27

when is a lentigo maligna melanoma diagnosed

Answer 27

when the malignant melanoma cells have entered the dermis and deeper layers of skin

Question 28

presentation of lengtio maligna melanoma

Answer 28

* Large size (\>6mm), irregular, variable pigmentation and smooth surface

Question 29

nodular malignant melanoma

Answer 29

* Most aggressive type, grows rapidly from the start. Presents as rapidly growing pigmented nodule which bleeds or ulcerates. * Has a vertical growth phase, which is more dangerous than the horizontal growth phase

Question 30

what contributes to prognosis, along with Breslow depth

Answer 30

ulceration

Question 31

what suffix is used in tumour staging to represent ulceration

Answer 31

B

Question 32

treatment options for melanoma

Answer 32

* primary excision * advanced disease may require chemo, immunotherapy or genetic therapies

Question 33

how much around the lesion must be cleared

Answer 33

* If in-situ then clear by circa 5mm * If invasive but \<1mm thick: 1cm clearance * If invasive and \>1mm thick: 2cm clearance

Question 34

indications for sentinel node biopsy

Answer 34

\>1mm thick or thinner with mitoses

Question 35

mitotic rate

Answer 35

reflects cellular proliferation within the primary tumour, is an important predictor of survival

Question 36

which mutation is often found in acral melanomas, and which drug targets it

Answer 36

c - kit mutation, imatinib

Question 37

which mutation is often found in melanomas on intermittently sun exposed skin

Answer 37

BRAF, stimulates MAPK pathway which stimulates cell division

Question 38

drugs that target BRAF

Answer 38

dabrafenib and vemurafenib

Question 39

what may improve responses to BRAF inhibitors etc

Answer 39

MEK inhibitor eg Tramatenib