dermatology Flashcards
what layer of the skin is affected by basal cell carcinoma?
the basal layer of the epidermis
what is the prognosis of BCC and why?
good because they develop slowly and rarely metastasise
what are the 3 main types of basal cell carcinoma?
nodular BCC
superficial BCC
morpheaform BCC
what is the most common type of BCC?
nodular BCC
where does nodular BCC usually present?
on the face
what is the clinical appearance of nodular BCC?
pearly shiny papule or nodules w/ small telangiectasis and rolled edges and someones a depressed centre
what is the second most common type of BCC?
superficial BCC
how does superficial BCC usually present?
as a plaque or patch of well defined scaly pink skin
where do superficial BCCs usually present?
on the trunk or extremities
what is the least common type of BCC?
morpheaform BCC
how does morpheaform BCC usually present?
as a poorly defined pale scar or indurated plaque
which type of BCC has the worst prognosis and why?
morpheaform BCC because it can subclinically destroy surrounding tissue
what is the main treatment goal of BCC?
complete removal
other than complete surgical resection what are the other management options for BCC?
topical 5 fluoro-uracil
cryotherapy
photodynamic therapy
where does squamous cell carcinoma occur?
in the squamous keratinocytes in the epidermis (the outermost layer of the skin)
where do SCCs most commonly occur?
in sun exposed areas such as the lips, back of hands, upper part of face or scalp
what are the 3 characteristic features of SCC?
bleeding
itching
crusting
what are the 2 pre cancerous lesions that can progress to SCC?
Bowens disease
actinic keratosis
what is Bowens disease?
SCC in situ - the cancerous cells are confined to the epidermis
what is actinic keratosis?
a pre cancerous scaly lesion
what is the first line management for Bowens disease?
restrictive therapies:
- cryotherapy
- topical 5 fluoro-uracil
what is the first line management for invasive SCC?
surgical excision w/ minimum of 4mm margins
what is the treatment of choice of SCC in cosmetically sensitive areas?
Mohs surgery
what causes melanoma?
uncontrolled proliferation of melanocytic stem cells
what are the 3 growth phases of melanoma?
in situ: the tumour is confined to the epidermis
invasive: the tumour has spread to the dermis
metastatic: the tumour has spread to other tissues
what are the 4 subtypes of melanoma?
superficial spreading melanoma
nodular melanoma
lentigo maligna melanoma
aural lentiginous melanoma
what is the most common subtype of melanoma?
superficial spreading melanoma
how does superficial spreading melanoma progress?
initially grows horizontally (radial growth phase) and this presents as a flat irregular pigmented lesion that slowly enlarges
as invasion continues, growth may become vertical
what is the most aggressive subtype of melanoma?
nodular melanoma
how does nodular melanoma progress?
malignant cells invade vertically, presenting as a nodule that grows rapidly (weeks to months)
often bleeds or ulcerates
what is lentigo maligna?
a precursor lesion to lentigo maligna melanoma that is directly related to sun damage
how does lentigo maligna present?
as a patch of discoloured skin that grows slowly and becomes more atypical
where does acral lentigenous melanoma occur?
on the palms, soles or under the nails
how does acral lentigenous melanoma present?
as a flat pigmented lesion that slowly enlarges
what is breslows thickness?
a measure of the thickness of invasive melanoma in mm from the granular layer to the deepest tumour layer
at what breslows thickness is a sentinel node biopsy needed?
> 0.8mm
what is the management of stage 0 melanoma (in situ)?
wide local excision w/ at least 0.5cm margin
what is the management of stage 1 melanoma (melanoma <2mm thickness)?
wide local excision w/ at least 1cm margin
what is the management of stage 2 melanoma (melanoma >2mm thickness or >1mm thickness w/ ulceration)?
wide local excision w/ at least 2cm margins
what is the management of stage 3 melanoma (melanoma spread to involve local lymph nodes)?
wide local excision w/ lymphaedenectomy
