Melanoma Flashcards
what are the two types of melanoma
- melanoma
2. non-melanoma
what does malignant melanoma arise from?
arises from melanocytes
genetics of malignant melanoma
CDKN2A (tumour suppressor) and CDK4 (oncogene, cell cycle with Rb)
four types of malignant melanoma
- superficial spreading
- acral/mucosal lentiginous
- lentigo maligna
- nodular
sites for superficial spreading melanoma
trunk and limbs
sites for lentigo maligna melanoma
sun damaged areas, commonly face, neck, scalp
describe nodular melanoma
- commonest cancer
- slow growing nodule
- pearly
- telangiectasia
- excellent prognosis
- surgical excision
how does SSM, A/MLM and LMM grow?
- grow as macules either as in-situ or with dermal micro invasion (RGP)
- can invade dermis (VGP)
is nodular melanoma a VGP?
yes
presentation of melanoma
Asymmetry ill-defined border two or more colours wide diameter, non symmetrical speed of change
when is speed of change the most important factor in presentation?
atypical mole syndrome
spread of malignant melanoma
- dermal lymphatics
- regional lymph nodes
- blood
diagnosis of malignant melanoma
- Breslow thickness (deepest part of the tumour from granular layer)
- other prognostic indicators are ulceration, mitotic rate, invasion, lymph node involvement
management of malignant melanoma
- targeted therapy e.g. vemurafenib, dabrafenib
- excision of lesions
- sun protection measures
- chemo/radiotherapy
example of a benign epidermal tumour
seborrheic keratosis (basal cell papilloma)
define seborrheic keratosis
benign proliferation of epidermal keratinocytes
sites of seborrheic keratosis
face
trunk
presentation of seborrheic keratosis
ageing skin well-defined stuck on appearance (greasy hyperkeratotic surface) acanthosis sign of Leser-Trelat
management of seborrheic keratosis
reassurance
cryotherapy if troublesome
what is special about precancerous dysplasias
they show squamous dysplasia
examples of precancerous dysplasia
- Bowen’s disease
- actinic keratosis
- viral lesions
describe Bowen’s disease
full thickness dysplasia of epidermal keratinocytes (SCC in situ, no dermal invasion)
presentation of Bowen’s disease
scaly patch/plaque
irregular border
legs
can mimic inflammatory conditions
management of Bowen’s disease
imiquimod cream
surgical management
diagnosis of Bowen’s disease
diagnostic biopsy
define actinic keratosis
common precursor of SCC (low rate of progression)
presentation of actinic keratosis
sun-exposed sites
scaly patch
several atypical lesions- Bowenoid
management of actinic keratosis
non-surgical
describe precancerous dysplasia viral lesions
associated with HPV 16
found on anogenital skin
list of management options for precancerous dysplasia
- surgery
- cryotherapy
- 5-fluorouracil cream
- imiquimod
- PDT
examples of invasive malignancies that are non-melanoma
- basal cell carcinoma
2. squamous cell carcinoma
genetics of BCC
mutations in PTCH1
hedgehog signalling pathway
location of BCC
sun exposed sites
presentation of BCC
slow growing
painless and often ignored
locally destructive
no metastasis
three types of BCC
nodular
superficial
infiltrative (morphoeic)
management of basal cell carcinoma
vismodegib excision imiquimod PDT cryotherapy
diagnosis of BCC
skin biopsy
presentation of nodular BCC
pearly nodule
blood vessels visible
presentation of superficial BCC
erythematous, scaly, irregular bordered plaque
pearly whipcord margin
presentation of infiltrative BCC
waxy
scar-like plaque
indistinct border
associations of squamous cell carcinoma
elderly immunosuppressed chronic leg ulcers chronic lupus vulgaris xeroderma pigmentosum dystrophic variant epidermolysis bullosa
presentation of SCC
hyperkeratotic wart/ulcer/lump
fast growth
painful
bleeding
spread of SCC
can spread locally to bone and lymph nodes
management of SCC
excision
describe miscellaneous tumours
enormous range that can arise from sweat glands, smooth muscle, arrector pili, lymphatics, Langerhans, Merkel and fat
five risk factors for skin cancer development
sun exposure genetic predisposition immunosuppression environmental carcinogens phototoxic drugs
how does sun exposure cause skin damage
multiple p53 mutations
UVB direct DNA damage
UVA indirect oxidative damage deeper into the skin
depletes Langerhans
genetic predispositions to skin cancer
- DNA repair syndrome xeroderma pigmentosum
- albinism: congenital AR absence of melanin
- Gorlin’s syndrome: AD condition with multiple BCC
- recessive dystrophic epidermolysis bullosa
examples of phototoxic drugs
voriconazole thiazide diuretics NSAIDS anti-TNF azathioprine
describe Gorlin’s syndrome
naevoid basal cell carcinoma
describe albinism
absence or defect of tyrosine
visual problems too due to lack of pigment (photophobia, nystagmus, amblyopia)
