Flashcards in Malignant Melanoma Deck (84)
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?
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?
What is BRAF?
A serine/threonine protein kinase activating the MAP kinase/ERK-signalling pathway
What % of melanomas have activating BRAF mutations?
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?
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?
What are the risk factors for malignant melanoma?
- Previous primary invasive melanoma
- 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?
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?
- Irregular border
- Irregular colour
- Diameter greater than 7mm
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
- 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?