Dermatology - skin cancer Flashcards
What is the most common cancer in Australia?
Pancreatic
Lol Jks - skin cancer (non melenoma)
What portion of people will get melanoma in Australia by age 85?
1 in 15 men
1 in 25 women
What percentage of cancers are melanoma?
10%, 3.6% cancer deaths
What portion of non-melenoma skin cancers are due to sun exposure?
99% (mostly immunosuppression for the rest)
What are the causes of melenoma?
Sun exposure
Tanning beds
Giant congenital naevi
Genetic (CDK2NA mutations)
What are risk factors for melenoma?
Men (2x women)
Elderly
Fair-skinned
Sun exposure
Family history (one affected 1 st degree relative=2x risk for melanoma)
Multiple naevi (>100 naevi = 7x melanoma risk)
Past skin cancer (melanoma = x10 NMSC = x4)
What are the subtypes of BCCs?
Superficial
Nodular
Morpheic
Where do superficial BCCs commonly occur?
most common on trunks and limbs
Where do nodular BCCs commonly occur?
most common in head and neck?
How do morphoeic BCCs appear?
pale and scar like
often appear smaller that they are and less invasive
How do you make a diagnosis of BCC/ SCC?
clinical + biopsy
how do you biopsy a suspected BCC or SCC?
shave or punch biopsy
What are the treatment options for BCCs/ SCCs?
Surgery
Radiotherapy
Cryotherapy (only for certain ones)
Topical creams (only for certain ones)
Phototherapy (only for certain ones)
What are the advantages of surgery as a treatment for skin cancer?
best cure rate (95%)
Histological evaluations of the margins
Good cosmesis and function
What margins are needed for SCC/ BCC?
3-4mm
What are the reasons you would use radiotherapy for a BCC/ SCC?
older people (>60)
Surgery contraindicated
To avoid keloid scar
To avoid mutilating surgery
Palliation
Where do SCCs commonly occur?
Sun exposed skin - hands, face, neck, lower legs
What are the subtypes of SCCs? (including precursors)
Solar keratosis
Bowens disease
Keratoacanthoma
Invasive squamous cell carcinoma
High risk SCC
What are Solar keratosis?
Pre-runner to SCC
What is the other name for solar keratosis?
actinic keratosis
What are the clinical features of solar keratosis?
Plaques,
Skin coloured or red/ pigmented
can be tender or itchy, sting when sweaty
How are solar keratosis most commonly treated?
cryotherapy (sometimes creams)
What is Bowen’s disease?
SCC in situ
confined to epidermis, no potential for metastasis
What are the clinical features of Bowen’s disease
irregular scaly plaques of up to several centimetres in diameter. They are most often red but may also be pigmented.
Can grow under the nails
Often confused for psoriasis or eczema
What skin cancers is cryotherapy suitable for?
BCC or solar keratosis, bowen’s disease on trunk or limbs
What is a keratoacanthoma?
A skin lesion. It has a characteristic morphology with a keratin filled sac/ centre. Some pathologist believe it is a well differentiated SCC
What is the natural history of keratoacanthomas?
They grow quite quickly over weeks, and then will regress.
They are difficult to distinguish from more invasive cancers clinically, so are often surgically removed anyway.
What skin cancers is 5 flourouracil treatment suitable for?
solar keratosis
What skin cancers is imiquimod treatment suitable for?
solar keratosis or superficial BCC
What skin cancers is photodynamic therapy treatment suitable for?
solar keratosis or superficial BCC or Bowen’s disease
What makes a SCC high risk?
○ >2cm
○ Sites: ears, lips, scalp
○ Retreatment needed
○ Immunosuppressed patient
What is the metastatic chance in a high risk SCC?
10-20%
What is the metastatic chance in a low risk SCC?
< 1%
What is the recommended follow up for someone who has had an SCC or BCC removed?
yearly skin check for BCC
2x yearly for SCC
What are the melanoma subtypes?
Superficial spreading Nodular Lentigo maligna Acral lintiginous - hands and feet Subungual - nail Amelanotic melanomas
What is a lentigo mealigna also known as?
melanoma in situ, or Hutchinson’s melanocytic freckle
What are the clinical features that suggest a melanoma?
Asymmetrical shape
Border irregularity
Colour irregularity
Diameter > 7mm
Evolution (change in size ,shape or colour)
How should a suspected melanoma be biopsied?
shave or punch biopsy generally
incisional biopsy if large
2mm margins wanted
What is the most prognostically/ clinically important histological classification of melanomas?
Breslow thickness
What surgical margins should be achieved with a melanoma?
Melanoma in situ: 0.5cm
Breslow thickness < 1mm = 1cm margin
Breslow thickness > 1mm = 2cm margin
Should you perform a sentinal lymph node biopsy for melanoma?
controversial
only consider if > 1mm breslow thickness
What is the recommended follow up for someone who has had an melanoma removed?
if <2mm thick then 2x/ year for 5 years, then yearly
if thicker or mets then every 3-4 months for 5 years then yearly
What is the most common subtype of melanoma?
superficial spreading
