skin cancer Flashcards
what gene mutations increase risk of melanoma?
CNKN2A
MC1R
risk factors for melanoma?
light skin
red hair
DNA repair defects
what phenotypes increase risk?
over 100 melanocytic nevi
what, in melanoma, is a natural inhibitor of t cell activation
CTLA-4
it removes the costimultory signal
what type of growth is seen in superficial spreading melanoma?
first hotizontal then vertical growth
where is superficial spreading melanoma seen?
trunk of men
legs of women
where are nodular melanomas found?
trunk
head and neck
what type of growth is seen in nodular melanoma?
no horizontal just vertical
what does lentigo maligna present as
slow growing assymetric brown macula with an irrecular border ad colour variation
where does acral lentiginous melanoma occur?
palms and soles
around nails
what is the abcde of melanoma?
assymetry border irregularity colour variation diameterr over 5mm evolving
3 differentials of melanoma?
bcc
seborrhoeic keratosis
dermatofibroma
what are poor prognistic factors for melanoma?
increased breslow thickness ulceration increased age male trunk, head, neck
how is melanoma investigated?
dermoscopy (not in isolation)
history and cinical exam
management of melanoma?
primary excision to subcutaneous fat then biopsy
then wide excision if cancer
when is sentinel lymph node biopsy offered?
Pt1B+
when is imaging offered in melanoma?
stage 3+
or 2c without sentinel biopsy
what is given for metastatic melanoma?
ctla4 inhibition
braf ingibitor
chemo
what is the spectrum of kerotinocyte disorders?
actinic keratosis
bowens
invasive scc
what is bowens?
squamous cell carcinoma in situ
what is a significant risk factor of bcc?
uv radiation
how does bcc spread?
proteolytic activity - metalloproteinases and collegenases
what mutation is seen in bcc
loss of function in ptch gene in chromosome 8q
4 genetic syndromes which increase risk of keratinocyte carcinomas?
xeroderma pigmentosum (sensitivity to sunlight)
OCULOCUTANEOUS ALBINISM
muir torre syndrome
nevoid basal cell carcinoma
what is seen in actinic keratosis?
atypical keratinocytes confined to epidermis
how is actinic keratoses diagnosed?
punch biopsy
what is seen in bowens disease?
lesion is an erythmatous scaly patch or slighly elevated patch
treatments for actinic keratoses and bowens?
5 fluorouacil cream
cryotherapy
imiquimod cream
excision
what does scc look like?
erythmatois - skin colooured
papule
exophytic
eulceration
what looks similar clinically and histologically to scc?
keratoacanthoma
how is scc investigated?
clinical dianosis enough
biopsy
uss of regional lymph nodes
how is scc treated?
excision
radiotherapy
how does nodular bcc present?
shint pearly papule
how is bcc investigated
clinical dianosis often sufficient
maybe biopsy
differentials of bxx
squamous cell carcinoma
sebaceous carcinoma
merkel cell carcinoma
how is bcc treated?
surgical excision
if recurrent etc then microhraphic surgery
what is ctcl
groups of neoplasms of skin homing t cells
3 stages of mycosis fungoides
patch stage
plaque stage
tumour stage
how is mycosis fungoides diagnosed?
biopsy
clinincal
bloods
lymph node palaption
how is the plaque/patch stage treated
steriods, phototherapy, radiotherapy
if mycosis has spread what is the treatment?
systemic chemo
what is the triad of symptoms in sezary syndrome?
erythroderma
generalised lymphadenopathy
presence of neoplastic t cells
what are the criteria for szary diagnossis?
t cell clone in blood
expanded t cell population and CD4/CD8 ratio above 10
sezary cell ocunt of at least 1000 cells per microlitre
how is sezary treated?
systemic treatment
extracoroporal photophoresis
puva
steroids
what is merkel cell carcinoma?
malignant proliferation of anaplastic cells
associated with polyomavirus
red, rapid growing nodule
