225 - Malignant Melanoma Flashcards
(43 cards)
what is an unraised localise area of skin colour/texture change called?
macule
what is an elevation of skin
papule
what is an elevation of skin >5mm dia called?
nodule
what is a small blister
vesicle
what is a large blister >5mm of clear fluid called?
bulla
what is a blister with visible collection of free pus called?
pustule
what is a nodule consisting of an epithelial lined cavity filled with fluid or semi solid material called?
cyst
what is a transitory compressible papule or plaque of dermal oedema called?
wheal
what is a palpable plateau like elevation of skin called?
plaque
what is a accumulation of thickened horn layer keratin called?
scale
what is an area of skin loss extending into the dermis called?
ulcer
define eczema and how it presents?
skin barrier dysfunction of genetic susceptibility due to an abnormal immune response (IgE raised in 80% of atopics)
Itcy, red, weepy in acute, dry scaly and lichenified in chronic
what therapy is available for eczema?
irritant avoidance, emollient, soap substitute, topical steroid, topical calcineurininhibitors, bandages.
In more serious oral ABX/steroids, phototherapy, systemic therapies
what is the difference between irritant contact dermatitis and allergic contact dermatitis?
irritant - disruption of skin barrier, irritants damage keratinocytes + inflammatory mediators released
allergic - allergen picked up by APCs and causers immunological memory
what allergy tests exist?
- IGE RAST for tyI (intermediate) hypersensitivity
* Patch testing for TyIV (delayed) hypersensitivity
name topical steroids from weak to very potent
- H - weak - hydrocortisone
- E - mod potent - Eumovate (clobetasol butyrate)
- B - potent - Betnovate (betamethasone valerate)
- D - very potent - Dermovate (clobetasone proprionate)
how can sun exposure cause skin cancers?
*IV damages cellular DNA
*Tumour suppressor genes often disabled by UV - TP53 mutation (90% of SCCs), TP16 mutation
can be dysfunctional due to dentics +exoderma pigmentosum and basal cell naevus syndrome
who is at risk from malignant melanoma skin cancer?
- neoplasm of melanocytes or daughter cells
- middle aged females with white tyI skin
- sunburn, p16 tumour surpressor protein defects, congenital naevi or high numbers of atypical (irregular colour/shape) naevi
how does malignant melanoma develop?
- radial growth phase - outwards
* vertical growth phase - invade dermis and can metastasise
what are the signs of malignant melanoma and investigations?
- asymmetry
- irregular border
- irregular colour - black or blue
- diameter >6mm
- evolving
- nodular most dangerous - elevated, firm, growing
- excisional biobsy (Breslow thickness)
- imaging for mets
treatment for malignant melanoma?
surgical - increase margins (2-3 cm), sentinel node biopsy, adjuvant IFN-alpha
what is small cell carcinoma skin cancer and what causes it?
- invasive neoplasm of keratinocytes - Bowen’s disease (in-situ (not invaded through basal lamina). Affects elderly men with ty1 skin (70y/o)
- mostly due to sun damage afecting TP53 gene, viruses, heavy metals or immunosupression
- may develop from existing actinic keratoses
how does small cell carcinoma skin cancer present?
- red scaly lesions with endurated base on sun exposed areas. May ulcerate later
- investigations - biopsy, imaging for mets
treatments for small cell carcinoma skin cancer?
- exicisional biopsy with margins
- radiotherapy
- cryotherapy
- chemotherapy 5-fluorouracil cream
- photodynamic therapy
- immunotherapy - imiquimod cream