Pigmented Lesions Flashcards
What are the risk factors for melanoma?
Personal/family history Number of moles History of excess sun exposure Sunbed use Multiple sunburns Fair skin
Which type of UV light is thought to be responsible for melanoma development?
UVB
What are the major and minor criteria for changing moles?
Major:
- change in shape, size or colour
Minor:
- diameter >6mm
- bleeding
- sensory change
- inflammation
What is the rule for examining a mole?
ABCD:
- Asymmetry (shape or colour)
- Border (irregular e.g. indentation)
- Colour (>1 colour within the mole)
- Diameter > 6mm
What should you use to properly examine a mole?
Dermoscope
What are the 4 main types of malignant melanoma?
Superficial spreading (most common)
Lentigo maligna melanoma
Acral/mucosal lentiginous malignant melanoma
Nodular melanoma
What are the features of acral MM?
On palms, soles, nail beds and mucosa
What are the features of nodular MM?
Raised, thicker lesions
Spread more rapidly
What is the most important indicator for prognosis in MM?
Breslow thickness
What does the Breslow thickness measure?
Measures the deepest tumour cell from the granular layer of the epidermis
Describe the pattern of growth in MM?
First grow as macules within epidermis –> radial growth phase
Then invade dermis forming a lump –> vertical growth phase
EXCEPT nodular MM –> vertical growth from the outset
Describe the spread of MM?
Only metastasise once in the VERTICAL growth phase
- local dermal lymphatics (satellite deposits)
- regional lymph nodes
- haematological spread –> skin/soft tissue, heart, lungs, GI tract, liver, brain
What is the initial management of a suspected MM?
Narrow complete excision for confirmation of diagnosis and assessment of Breslow thickness
Then wide excision depending on Breslow thickness
If in situ (within epidermis), what should the excision margin be?
Clear by 5mm
If invasive but Breslow thickness < 1mm, what should the excision margin be?
1cm clearance
If invasive and Breslow thickness > 1mm, what should the excision margin be?
2cm clearance
When should a sentinel node biopsy be done?
If Breslow > 1cm or thinner with mitoses
What are ephilides?
Freckles - patchy increase in melanin pigmentation after UV exposure
What are actinic/solar lentigines?
Age/liver spots - related to UV exposure
Face, forearms and dorsal hands
Look like large freckles
What are melanocytic naevi and what are the different types?
Moles
- can be congenital but most are acquired in first 2 decades
- usually type, dysplastic, spitz, blue, halo
What are the features of congenital melanocytic naevi?
Usually larger than acquired type
If very large garment type (> 20cm) –> risk of melanoma
What are the features of dysplastic naevi and what is its malignant potential?
> 6mm, varied pigment, border asymmetry
If familial (lots of dysplastic naevi, Fox of MM) --> very high lifetime risk of melanoma
What is a halo naevus?
Peripheral halo of depigmentation around more due to inflammatory regression
What is a blue naevus?
Blue/black colour, entirely dermal mole
What is a spitz naevus?
Pink colour due to prominent vasculature
Used to be called benign juvenile melanoma
- occurs in children, closely mimics melanoma but entirely benign
