Benign and Malignant melanocytic lesions Flashcards
What are melanocytes?
found in epidermis produce melanin give your skin colour
What is a naevus (or mole)?
Naevus refers to an abnormal by benign proliferation of melanocytes in the skin
What is a congenital naevus?
present at birth uncommon
What is a junctional naevus?
maculardark
What is an intradermal naevus?
raised and skin colour
What is a melanoma?
malignant proliferation of pigment producing melanocytes of the skin
What are the risk factors for melanomas?
- fair skin (type 1/2)
- excessive sun exposure in childhood
- family history
- immunosuppressed patients
- patients with multiple atypical moles
- large congenital naevi
- old age
What important features associated with poor prognosis in melanomas?
lesions on head and neck man older age ulceration tumour thickness
What are the seven checklist points of melanomas?
1 - changing or irregular colour 2 - irregular shape, asymmetry 3 - changing size 4 - oozing, crusting or bleeding 5 - change in sensation, itching 6 - inflammation 7 - largest diameter >7mm
What is the ABCD rule for describing melanomas?
A - asymmetry
B - border
C - colour
D - diameter (most normal moles are <7mm diameter)
What are the different subtypes of melanoma?
Superficial spreading melanoma (SSM) - 70%
Lentigo maligna melanoma (LMM)
Acral Lentiginous
Nodular melanoma
What is SSM?
Superficial spreading melanoma
Where is SSM common?
Common on lower limbs in young and middle aged adults Related to intermittent high intensity UV exposure
men - commonly trunk
women - commonly legs
Where is nodular melanoma common?
common on trunk in young middle aged adults
related to intermittent high intensity UV exposure
What is acral lentigious melanoma?
common on palms, soles and nail beds in elderly population
more common in darker skin individuals (afro-carribeans)
no clear relation to sun exposure
What is lentigo maligna melanoma?
common on the face in elderly population related to long term cumulative UV exposure
What are the benign lesions that can mimic melanoma?
atypical moles blue naevus seborrhoeic wart pigmented BCC dermatofibroma pyogenic granuloma
What is the management of melanoma once a diagnosis has been confirmed?
Wide local excision using 1-2cm peripheral margin
Lymph node clearance for regional metastasis
No specific treatment for distant metastasis
What are congenital melanocytes naevi?
Melanocytes which fail to mature or migrate in utero
What are acquired melanocytic naevi?
develop after birth - usually before age of 25
What are the different types of melanocytes naevi?
junctional
- macular compound
- warty dermal
- smooth and dome shaped
halo naevus
- undergoing recession, benign often blue naevus
- melanocytes in dermis, usually benign, often extremities
What is the 5 year survival for melanocytes naevi?
Breslow thickness
in-situ - 100%
depth less than 1.5mm - 90%
1.50-3.00mm - 60%
greater then 3.00mm - 40%
What are the different types of congenital naevus?
giant congenital naevi - increased risk of melanoma
cafe au lait - congénital tan macule, usually oval in shape
How are lentigo maligna/ lentigo maligna melanoma managed?
surgical excision with 5mm margin (due to risk of melanoma)
excellent prognosis
