Malignant Melanoma Flashcards
What is a malignant melanoma?
Cancerous growth of melanocytes
Where do malignant melanomas arise from?
The vast majority arise from skin, but malignant melanomas have been described in nearly every organ of the body
Where are normal melanocytes found?
In the basal layer of the epidermis
Are more melanocytes found in black or white skin?
The same
How do melanocytes differ in black and white skin?
Melanocytes in black skin produce much more melanin
What do non-cancerous growths of melanocytes result in?
Moles and freckles
What mutation is associated with malignant melanoma?
BRAF mutations
What is BRAF?
A serine/threonine protein kinase activating the MAP kinase/ERK-signalling pathway
What % of melanomas have activating BRAF mutations?
50%
What has BRAF V600 been implicated in?
Different mechanisms underlying the development of melanomas
What are the types of malignant melanomas?
- Superficial melanoma
- Nodular melanoma
- Lentigo maligna melanoma
- Acral lentiginous malignant melanoma
What are the characteristics of superficial melanomas?
Large, flat, irregularly pigmented lesion which grows laterally before vertical invasion develops
What is the most invasive type of malignant melanoma?
Nodular
How do nodular melanomas present?
Rapidly growing pigmented nodule which bleeds or ulcerates
What is a lentigo maligna?
Melanoma in situ
It is not the same as a lentigo maligna melanoma
What is a lentigo maligna melanoma?
When a patch of lentigo maligna develops a papule or nodule, signally an invasive tumour
How does acral lentiginous malignant melanoma present?
Pigmented lesions on palm, sole, or under the nail
When does acral lentiginous malignant melanoma present?
Late
What are the risk factors for malignant melanoma?
- Previous primary invasive melanoma
- Naevi
- Sun exposure
- Pale Caucasian skin
- Family history of melanoma
- Past pesticide exposure
- Higher socio-economic group
What % of people with malignant melanoma will develop a further lesion, or a different type of skin cancer?
3-5%
What kind of sun exposure in particular increases the risk of malignant melanoma?
- Sharp, short bursts of acute exposure in childhood
- Severe sunburn in childhood
- Past sunbed use, especially before age 30
What features of pale skin indicate an increased risk of malignant melanoma?
- Poor ability to tan
- Freckled complexion
What are the features of the appearance of malignant melanoma?
- Asymmetrical
- Irregular border
- Irregular colour
- Diameter greater than 7mm
- Evolving
When should people be referred under the 2WW for malignant melanoma?
If they have a suspicious pigmented skin lesion with a weighted 7-point checklist score of 3 or more
How is a persons 7-point checklist score determined?
Major features score 2 points each, and minor features score 1 point each
What are the major features on the 7-point checklist score for malignant melanoma?
- Change in size
- Irregular shape
- Irregular colour
What are the minor features on the 7-point checklist score for malignant melanoma?
- Largest diameter 7mm or more
- Inflammation
- Oozing
- Change in sensation
What are the primary investigations for malignant melanoma?
- Visual inspection
- Removal for histology where necessary
How is a diagnosis of malignant melanoma made?
Excisional biopsy
What further investigations may be done in malignant melanoma once a diagnosis is established?
- Sentinel lymph node biopsy
- CXR and liver ultrasound, or CT scan of chest, abdomen, and pelvis
- Blood tests
- Bone scan
What blood tests should be done in the further investigation of malignant melanoma?
- FBC
- LFTs
- LDH
When should a bone scan be done in the further investigation of malignant melanoma?
If there is indication of bone disease
What is Tx in malignant melanoma?
Primary tumour cannot be assessed
What is T0 in malignant melanoma?
No evidence of primary tumour
What is Tis in malignant melanoma?
Tumour in situ
What is T1 in malignant melanoma?
Thickness 1mm or less
What is T1a in malignant melanoma?
Without ulceration in mitosis <1/mm^2
What is T1b in malignant melanoma?
With ulceration
What is T2 in malignant melanoma?
Thickness 1.01-2mm
What is T2a in malignant melanoma?
Without ulceration
What is T2b in malignant melanoma?
With ulceration
What is T3 in malignant melanoma?
Thickness 2.01-4mm
What is T3a in malignant melanoma?
Without ulceration
What is T3b in malignant melanoma?
With ulceration
What is T4 in malignant melanoma?
Thickness >4mm
What is T4a in malignant melanoma?
Without ulceration
What is T4b in malignant melanoma?
With ulceration
What is N1 in malignant melanoma?
One metastatic node
What is N1a in malignant melanoma?
Micromets
What is N1b in malignant melanoma?
Macromets
What is N2 in malignant melanoma?
2-3 mets
What is N2a in malignant melanoma?
Micrometastasis
What is N2b in malignant melanoma?
Macrometastasis
What is N3 in malignant melanoma?
More than 4 metastatic nodules, or matted nodes
What is M1 in malignant melanoma?
Evidence of metastasis
What is M1a in malignant melanoma?
Distant skin, subcutaneous, or nodal mets
What is M1b in malignant melanoma?
Lung mets
What is M1c in malignant melanoma?
All other visceral mets, or any distant mets with elevated serum LDH
What can happen once melanoma cells have reached the dermis?
They may spread to other tissues via the lymphatic system
Where can melanoma cells spread via the lymphatic system?
- Local lymph nodes
- Bloodstream
- Other organs
Where can metastases from malignant melanoma occur?
Virtually anywhere, at any time
What are the most common sites for metastases of malignant melanoma?
- Lymph nodes
- Liver
- Lung
- Bone
- Brain
What are the management options in stage 0 malignant melanoma?
- Surgery
- Topical imiquimod
What should the margin be when excising stage 0 malignant melanoma?
At least 0.5cm
When should topical imiquimod be considered to treat stage 0 melanoma?
If surgery to remove the entire lesion with 0.5cm clinical margin would lead to unacceptable disfigurement or morbidity
What should you consider after treatment for stage 0 melanoma?
Repeat skin biopsy for assessment after treatment to check it has been effective
How is stage 1 melanoma managed?
Excision
What margin is required for excision of stage 1 melanoma?
At least 1cm
How is stage 2 melanoma managed?
Excision
What margin is required for excision of stage 2 melanoma?
At least 2cm
When should therapeutic lymph node dissection be offered in stage 3 melanoma?
In people with palpable 3b or 3c melanoma, or nodal disease detected by imaging
What is the first line option if palliative treatment for in-transit melanoma metastases is needed?
Palliative surgery
What are the options for the palliation of in-transmit melanoma mets if surgery is not feasible?
- Systemic therapy
- Isolated limb infusiion
- Isolated limb perfusion radiotherapy
- Topical agent, e.g. imiquimod
What can be used in the palliation of superficial melanoma skin metastases?
Topical imiquimod
What can be used in the palliation of metastases in the skin form tumours of a non-skin origin?
Electrochemotherapy
What are the management options in stage 4 melanoma?
- Surgery or other ablative treatments
- Systemic anti-cancer treatments
What is the purpose of surgery in stage 4 melanoma?
To prevent and control symptoms
What systemic anti-cancer treatments can be used in melanoma?
- Targeted treatments
- Immunotherapy
- Cytotoxic chemotherapy
Give 2 targeted treatments for melanoma?
- Dabrafenib
- Vemurafenib
When are targeted treatments recommended for melanoma?
For treated unresectable or metastatic BRAF V600 mutation-positive melanoma
Give an immunotherapy for melanoma
Ipilimumab
When is immunotherapy recommended in melanoma?
For treating unresectable or metastatic melanoma in people who have received prior therapy
Give a cytotoxic chemotherapy for melanoma
Dacabazine
When is cytotoxic chemotherapy recommended in melanoma?
For stage IV metastatic melanoma if immunotherapy or targeted therapy is not suitable