Melanoma Flashcards
Define melanoma
Malignancy arising from neoplastic transformation of melanocytes, the pigment forming skin cells
Aetiology of melanoma
3
DNA damage caused by ultraviolet radiation leads to neoplastic transformation
50% arise in existing naevi
50% arise in previously normal skin
Histopathological types of melanoma
4
Superficial spreading
Nodular
Lentigo maligna
Acral lentiginous
Histopathological types of melanoma - superficial spreading
(70%)
Arises in a pre-existing naevus, expands in a radial fashion before a vertical growth face
Histopathological types of melanoma - nodular
3
(15%)
Arises de novo
AGGRESSIVE
No radial growth phase
Histopathological types of melanoma - lentigo maligna
4
(10%) More common in elderly w/ sun damage Large flat lesions Progress slowly Usually on the face
Histopathological types of melanoma - acral lentiginous
2
(5%)
Arise on palms, soles & subungual area
Most common type in NON-WHITE populations
Epidemiology of melanoma
prevalence x2, group
Leading cause of death from skin disease
Steadily increasing in incidence
WHITE races have 20x risk compared to non-whites
Presenting symptoms of melanoma
5
Change in size, shape or colour of a pigmented skin lesion Redness Bleeding Crusting Ulceration
Signs of melanoma on physical examination
5
ABCDE criteria for examining moles: A - asymmetry B - border irregularity C - colour variation D - diameter > 6mm E - elevation/evolution
Investigations for melanoma
5 types
Excision biopsy
Lymphoscintigraphy
Sentinel lymph node biopsy
Staging
Bloods
Investigations for melanoma -excision biopsy
Histological diagnosis & determination of Clark’s levels & Breslow thickness
Investigations for melanoma - lymphoscintigraphy
Radioactive compound injected into lesion & images taken over 30 mins to trace lymph drainage & identify sentinel nodes
Investigations for melanoma - sentinel lymph node biopsy
Check for metastatic involvement
Investigations for melanoma - staging
US, CT, MRI, CXR
