Skin cancer Flashcards
Most common modalities for examining skin cancers
Imaging and skin cancer
What is a melanoma?
Malignant tumour arising from melanocytes
Where can melanomas form?
Skin
Mucosal surfaces e.g. vaginal, bowel, oral, conjunctiva
Due to abnormal migration of melanocyte precursors
Genetic risk factors of melanoma
Family history
DNA repair defects - xeroderma pigmentosum
Pale skin
Red hair
Environmental risk factors of melanoma
Sun/UV exposure
Immunosuppression
Phenotypic risk factors of melanoma
> 100 moles
atypical moles
nevi = moles
What are some specific genetic mutation that is a risk factor for melanoma?
CDKN2A Mutation - tumour suppressor
cyclin kinase
What are four subtypes of melanoma?
LANS
Lentigo Maligna,
Acral Lentiginous,
Nodular,
Superficial Spreading
some are unclassifiable
What is the most common type of melanoma
Superficial spreading
Can arise de novo or from an old mole
Where do superficial spreading melanomas arise?
Trunk or Legs
Why is depigmentation in melanoma tumours found?
Shows as grey or hypopigmented area
Where there has been an immune response against the tumour
Describe the growth pattern of superficial spreading melanoma
First horizontal growth and then vertical growth
What is the horizontal growth in superficial spreading melanomas characterised by
asymmetry
colour variation
border irregularity
Where on the body do nodular melanomas occur
Trunk
head
neck
Describe the appearance of nodular melanomas?
Blue to black nodules (may also lack in colour), rapid development
more common in men
Describe the growth pattern of nodular melanomas?
Only vertical growth - therefore spherical shape
Deeper and more likely to metastasize
ABCDE of melanoma self detection
(nodular melanoma does not follow this rule)
Asymmetry
Border irregularity
Colour variation
Diameter >5/6mm
Evolution: change in size, shape, colour
Who does Lentigo maligna mainly affect
> 60yrs
chronically sun damaged skin
What is the appearance of lentigo maligna melanoma?
Slow growing, asymmetric brown/black macule with irregular border (not well defined)
Lentigo maligna vs Lentigo maligna melanoma?
Lentigo Maligna - in situ
Lentigo Maligna Melanoma - invasive
What body parts are affected by acral lentiginous melanoma
palms/soles - ulceration and scarring
nail apparatus - lines called melanonychia
Who is most affected by acral lentiginous melanoma
Affects all skin types equally
Though darker skinned people are more likely to be diagnosed with this over other types
Amelanotic melanoma
No pigment
appears pink
What are poor prognostic features for melanoma?
Increased Breslow thickness (>1mm) - main one!!!, Ulceration,
Age,
Lymph Nodes involvement
What are some differential diagnoses for melanoma?
Basal cell carcinoma, Seborrhoeic keratosis, Dermatofibroma
What is dermoscopy?
Tool to microscopically examine skin
Improves diagnosis
What is Breslow thickness?
Thickness of tumour from stratum granulosum