Malignant Melanoma Flashcards
Are melanomas benign or malignant?
highly malignant
Where do melanomas arise from?
the melanocyte layer of the skin situated in the basal layer of the epidermis
Summarise the aetiology of melanoma:
ultraviolet radiation causes melanocytic stem cells to undergo a genetic transformation so that they proliferate uncontrollably
What is the medical term for moles?
benign melanocytic naevi
What is the medical term for freckles?
lentigines
Define ‘invasive’ melanoma:
where the tumour has penetrated into the dermis below
Define ‘in situ’ melanoma?
where the tumour is confined to the epidermis
What are the 4 types of melanoma?
- Superficial spreading melanoma
- Nodular melanoma
- Lentigo maligna melanoma
- Acral lentiginous melanoma
What is the most common type of melanoma?
superficial spreading melanoma
Describe the pattern of growth seen in superficial spreading melanoma:
1) they grow horizontally
2) they have a relatively long in situ phase
Where are superficial spreading melanomas found?
anywhere in the body but particularly the trunk in males and legs in females
What is the most aggressive type of melanoma?
nodular melanoma
Describe the pattern of growth seen in nodular melanomas:
they invade vertically rapidly
How do superficial spreading melanomas present?
flat, irregularly pigmented lesion that slowly enlarges
How do nodular melanomas present?
usually one colour (dark or blue) with a berry-like, symmetrical morphology
What percent of melanomas are nodular melanomas?
15 - 30 %
What is lentigo maligna melanoma?
melanoma formed from the precursor lentigo maligna, a patch of discoloured skin that grows slowly and becomes more atypical over time
Where does lentigo maligna usually occur?
Lentigo maligna usually occurs on the face or other areas of chronic sun exposure as an asymptomatic, flat, tan or brown, irregularly shaped macule or patch with darker brown or black spots scattered irregularly on its surface. In lentigo maligna, both normal and malignant melanocytes are confined to the epidermis.
How does acral lentiginous melanoma present?
flat, slowly enlarging pigmented lesion found on the palms, soles or under nails
Give 6 risk factors for melanoma:
1) skin cancer history or family history
2) pale skin and red hair
3) increasing age
4) high sun/UV exposure
5) high freckle density
6) large amounts of moles
What is the name given to melanomas with no pigment that present as pink/red lesions?
amelanotic melanoma
Give the 5 features of the ABCDE Criteria used to assess melanomas:
1) asymmetric shape
2) border irregularity
3) colour change
4) diameter
5) evolving - change in size, shape, colour, bleeding
Fill in the gap: most melanomas are under __mm
> 6mm
Give two differentials for melanoma:
1) dermatofibroma (pigmented harmless lump)
2) seborrheic keratosis
How does seborrheic keratosis present?
waxy, scaly dark lump
What type of referral should be used for suspected melanoma?
2 week referral
What is the name of the system used to stage melanomas based on their thickness?
Breslow’s thickness
Summarise the staging system for melanomas:
1) stage 0 - in situ
2) stage 1 - <2mm thickness
3) stage 2 - >2mm thickness of >1mm thickness with ulceration
4) stage 3 - spread to local lymph nodes
5) stage 4 - metastases to distant sites
What is the main management method for melanomas?
wide local excision
What investigation can be used to check for local spread of melanomas?
sentinel lymph node biopsy
What is the % survival rate for stage 4 melanomas?
7-19%
Name two immunotherapies that may be given to late stage melanomas that cannot be resected:
1) Nivolumab
2) Ipilimumab
What is the EFG system that is used for nodular melanomas?
E = Elevation, and
F = Firmness to touch, and
G = Growth. Persistent growth for over one month
Nodular melanoma can be brown, black, blue-black, and up to 50% are hypomelanotic (pink-red or skin-coloured). The surface can be smooth, rough, or crusted. Nodular melanoma often lacks dermoscopic clues, and the diagnosis should be considered in any skin lesion demonstrating all of EFG:
