Benign and Malignant Melanocytic Lesions Flashcards
What are the risk factors for developing a malignant melanoma?
- FH
- PMH
- Severe sunburn in childhood
- Increased UV exposure
- Multiple dysplastic naevi
- Large congenital naevi
Using the ABCDE approach describe a classic malignant melanoma?
What is the 7 point check list when considering a MM?
An assymetrical lesion, with irregular borders, with a variable colour with different shades of brown, black etc.. In diameter it is >6mm and it is elevated above the skin.
- Changing colour
- Changing shape
- Changing size
- Bleeding
- Inflammtion
- Itching
- Diameter >7mm
What are the 2 major categories of naevi you can have?
Acquired (adolescents and early adulthood) or congenital
Which layer of the skin are melanocytes found?
The basal layer of the epidermis.
What are the different types of acquired naevi and describe the histology behind them?
Junctional: groups of melanocytes group together around the junctions between the epidermis and dermis. Appear as flat dark macules.
Compound: with age some of the groups of melanocytes will migrate further into the dermis whilst some will stay in the junction between the dermis and epidermis. They appear as brown dome shaped papules.
Intradermal: the melanocytes drop deeper into the dermis leaving the person with a skin coloured dome shaped papule. Most often seen in the elderly.
Describe the different layers of the skin?
What sun advice should you give to patients?
Too much sun exposure is bad for you and can increase your risk of developing skin cancer.
If you are going to be in the sun ensure you use sunscreen to protect against the damaging UV waves.
You should use a sunscreen with an SPF factor of at least 30 and you should reapply it every few hours.
Avoid going outside from 11am to 3pm when the sun is at its strongest
What is the following lesion (to help you can use the ABCDE approach)?
Junctional Naevus
Normal mole non invasive
What is the following lesion (to help you can use the ABCDE approach)?
Atypical Naevus: can be difficult to distinguish between MM, compare to surrounding moles to help and if still not sure always biopsy.
Not dangerous but those with atypical naevi have a slightly higher risk of malignancy
A: Symmetricalish
B: Irregular
C: Variable
D: <6mm
E: Flat
What is the following lesion (to help you can use the ABCDE approach)?
Superficial spreading malignant mealnoma.
Most common type of malignant melanoma 70%.
Rapidly invasive and spreads radially.
What is the following lesion (to help you can use the ABCDE approach)?
Intradermal Naevus
Non pathological usually found in the elderly
What is the following lesion (to help you can use the ABCDE approach)?
Lentigo Maligna (Lentigo maligna is a melanoma in situ that consists of malignant cells but does not show invasive growth.)
(Lentigo refers to a large freckle)
It will change over time and can eventually become malignant, it is found on sun exposed areas of skin.
Once it become malignant it is refered to as lentigo maligna melanoma
What is the following lesion (to help you can use the ABCDE approach)?
Acral lentigo melanoma
Rapidly invasive and more common in dark skinned individuals
What is the following lesion (to help you can use the ABCDE approach)?
Nodular Melanoma
Rare
Highly malignant (even worse prognosis than superficial spreading)
What is the following lesion (to help you can use the ABCDE approach)?
Compound Naevi
Benign
What is the following lesion (to help you can use the ABCDE approach)?
Seborrhaeic wart/keratosis (Seborrhoeic warts are harmless growths on the skin, which are very common in the elderly. They are often pigmented. Despite their name, seborrhoeic warts are nothing to do with sebaceous glands or viral warts. They are benign growths due to a build up of ordinary skin cells.)
Wart matte surface
What is the following lesion (to help you can use the ABCDE approach)?
Pyogenic granuloma
Looks very similar to a nodular melanoma exceot that it is red
