Malignant Melanoma Flashcards
What are risk factors for MM?
UV ecposure Sunburn Fair complexion MAny >50 melanocytic or dysplastic naevi Positive family history Previous mealnoma Old age
What are signs of MM?
ABCDEF
Asymmetry in the outline of the lesion
Border irregularity or blurring
Colour variation with shades of black, brown, blue or pink
Diameter >6mm
Evolution (changing)
Funny looking mole - mole that stands out or is different from others - good for identifying nodular melanoma which can be symmetrical, have regular borders and be uniform in colour but are elevated firm and growing
What is prognostic factors of MM?
Determined by Breslow thickness <1mm 95-100% 5 year survival 1-2mm 80-96 2.1-4 60-75 >4mm 50%
What are types of MM?
Superficial spreading melanoma
Nodular melanoma
Acral lentiginous melanoma
Lentigo maligna melanoma
Describe superficial spreading MM
Presents as a slowly enlarging pigmented lesion with colour variation and an irregular border
Initially growth is in the radial plane were the lesions remains thin but this may be followed by vertical invasion.
Common on trunks of men and legs of women
Most common
Describe nodular MM
Most aggressive type
No radial growth phase and lesions grow rapidly and invade deeply and metastasise early
Often darkly pigmented but may be amelanocytic
Typically affects sun exposed skin middle aged people
Red or back lump or lump which bleeds or oozes
Describe Lentigo maligna melanoma
Arises wtihin lentigo maligna
Growing mole with change in size shape or colour
Affects chronically sun exposed skin, older people
Describe acral lentiginous melanoma
Occurs on the palms, soles and subungual areas (under nails)
Most common type of melanoma i black and asian skin
Refer any new pigmented line in nail or growing under a nail especially if it extends fro the nailbed to the nail fold (Hutchinson’s nail sign)
What are the main diagnostic features?
Change in size Change in shape Change in colour Dimater > 6mm Inflammation Oozing, bleeding Altered sensation
What is management of MM?
Excision biopsy of suspicious lesion with a 2mm margin of normal skin around the lesion and a cuff off subcutaneous fa
This allows for histological diagnosis and measurement of tumour depth (Breslow thickness)
If malignant melanoma is confirmed, wider excision margin is taken (up to 3cm)
What margin of excision is required?
0-1mm lesion = 1cm
1-2mm lesion = 1-2cm
2-4mm lesion = 2-3cm
>4mm lesion = 3cm
What is a congenital melanocytic naevi?
Mole present at birth or in the early neonatal period
If >20cm there is increased risk for malignant change
What is acquired melanocytic naevi?
Present in childhood or in young adults and have a characteristic evolution
Start as flat evenly pigmented naevi
Nests of melanocytes collect along basal layer of epidermis
As melanocytes migrate to the dermis, models evolve into raised evenly pigmented dome shaped naevi
Finally the epidermal component is lost and moles change into pale brown papules disappearing in old age
What are halo naevi?
Common in adolescence
White halo develops around a benign melanocytic naevi
Not sinister and results from a loss of melanocytes by lymphocyte action
Halo naevi in adults may indicate melanoma elsewhere
Most common site in men? Women?
Men - back
Women - legs
