Skin cancer Flashcards
From what cells in the skin do basal cell carcinomas arise?
Keratinocytes in the basal layer of skin
From what cells in the skin do squamous cell carcinomas arise?
Keratinocytes in the suprabasal layers
How do basal cell carcinomas usually present?
A translucent, slow-growing lump or a non-healing ulcer
Painless
Why is delay in treatment of basal cell carcinoma less important than in other cancers?
Although they invade locally, they don’t spread more widely
How do squamous cell carcinomas tend to present?
A warty or crusted growth or a non-healing ulcer
May be painful
Hyperkeratotic
Which tends to grow faster: basal cell or squamous cell carcinoma?
Squamous cell
What is the most common cancer in 15-24 year olds?
Malignant melanoma
What is used to determine prognosis from malignant melanoma?
Breslow thickness
What is the prognosis of a malignant melanoma with a Breslow thickness >4mm?
5 year survival rate 50%
What does ABCDE stand for in terms of assessing skin lesions?
Assymetry
Border
Colour
Diameter
Evolution
What is the name given to a lesion with central ulceration and what is the diagnosis most likely to be?
Rodent ulcer
Basal cell carcinoma
Which skin cancer tends to have visible blood vessels in it’s lesions?
Basal cell carcinoma
What are precursor lesions to SCC?
Actinic keratoses
Bowen’s disease (carcinoma-in-situ)
What are the predisposing factors to development of skin cancer?
UV light from sunlight and sunbeds
Skin type
Moles
Family history/genetics
Some drugs
Other cancer
What kind of UV light exposure predisposes to development of BCC?
Intermittent exposure
What kind of UV light exposure predisposes to development of SCC?
Chronic exposure
What kind of UV light exposure predisposes to development of malignant melanoma?
Intermittent exposure
Which type of UV damage is reflected by sunburn and solar lentigo?
UVB damage
What type of damage occurs to skin with UVA exposure?
Solar ageing is attributed to the deeper penetration and solar elastosis of UVA
What is sunburn?
A protective mechanism whereby badly UV-damaged keratinocytes undergo apoptosis or programmed cell death
What are some examples of phototoxic drugs?
Voriconazole
Thiazide diuretics
Anti-TNF
NSAIDs
BRAF inhibitors
What are actinic/solar lentiges?
‘Age’ or ‘liver’ spots associated with UV exposure
Where are actinic lentiges found?
Face, forearms and dorsal hands
What is the risk of developing melanoma with a large congenital melanocytic naevi?
10-15%
What are the characteristics of a dysplastic naevi?
Generally >6mm diameter
Variegated pigment
Border asymmetry
What is this lesion?
Halo naevus
What are halo naevus and what are they associated with?
A mole surrounded by an area of depigmentation
Associated with vitiligo
What is seen on biopsy of halo naevus?
They show inflammatory regression and are overrun by lymphocytes
What is this lesion and what does it consist of?
Blue naevus - collection of dendritic rich spindle cells in the dermis that may mimic melanoma
What is this lesion?
Spitz naevus
What is a spitz naevus?
‘benign juvenile melanoma’
Consist of large spindle and/or epithelioid cells and may closely mimic melanoma, however most are entirely benign
In which gender are malignant melanomas most common?
Females 2:1
What features might raise suspicion that a lesion is a malignant melanoma?
New lesion develops in adulthood
Satellite lesions
Bleeding
Change in shape
Ulceration
Irregular pigmentation
What is the most common type of malignant melanoma?
Superficial spreading melanoma
Where do acral lentiginous melanomas arise?
Palms
Soles
Beneath nails
Which type of melanoma arises on sundamaged skin of the face, neck and scalp?
Lentigo maligna
What is ‘VGP’ in relation to malignant melanoma?
Melanoma cells invade the dermis forming an expansile mass with mitoses
Which type of melanoma are VGP only?
Nodular
What is RGP in relation to malignant melanoma?
Grows as macules when either entirely in-situ or with dermal microinvasion
What is the definition of Breslow thickness?
Depth of the deepest part of tumour from granular layer
What are poor prognostic indicators in malignant melanoma?
Increasing Breslow thickness
Satellite lesion formation
Ulceration
High mitotic rate
Lymphovascular invasion
Sentinel lymph node involvement
How does malignant melanoma spread?
Local dermal lymph nodes
Regional lymph nodes
Blood spread
What are satellite nodules with malignant melanoma?
MM spreading to dermal lymph nodes
Where do metastates from malignant melanoma spread?
Skin
Heart
Lungs
GI tract
Brain
Liver
What size of margin should be left when doing an excision of a malignant melanoma in situ?
5mm
What size of margin should be left when removing an invasive malignant melanoma <1mm thick?
1 cm
What size of margin should be left in excision of an invasive malignant melanoma >1mm thick?
2cm
When should a sentinel node biospy be performed with malignant melanoma?
>1mm thick or thinner with mitoses
What are these lesions?
Seborrhoeic keratosis
What are some of the precursors for squamous cell carcinoma and where are they commonly found?
Bowen’s disease: legs
Actinic keratosis: head/neck
Viral lesions: anogenital skin
What are the characteristics of Bowen’s disease?
Normally on lower leg
Scaly patch/plaque
Irregular border
No dermal invasion
More common in females
