This document summarizes key information about malignant melanoma and non-melanoma skin cancers. It discusses prognostic indicators for melanoma such as Breslow thickness and ulceration. The ABCDE criteria for identifying suspicious moles are outlined. The four main types of melanoma - superficial spreading, acral/mucosal lentiginous, lentigomaligna, and nodular - are described in terms of presentation and growth phases. Risk factors for skin cancer like sun exposure and genetics are covered. Prevention strategies like sunscreen use and clothing are also mentioned.

1. SkinCancer
W3 L1 & 5
Skin Cancer
Malignant Melanoma
- Nowthe most commoncancer in15-24 yearolds
- Twice as manyyoungwomengetmelanomabutmore mendie
- FastestincreasingcancerinScotland. More commonin females(2:1)
- Ugly ducklingsign –one mole outof manyis differentcolourandshape
- Can arise at any site butmostcommon onsun exposedsites –scalp,face,neck,arm, trunk,leg
- Rarelyoccur ineye,meninges,oesophagus,biliarytract,anus– cellsgettrappedin
embryogenesis
BreslowThickness – the depthfromthe granularlayerof the epidermistothe deepestmelanoma
cell.Itis usedasa prognosticindicatorof skincancer.
- BreslowThickness < 1 mm 5 yearsurvival is95-100%
- BreslowThickness 1-2mm 80%
- BreslowThickness > 4 mm 50%
- Metastases 5%
- Thinmelanomasare cured.Earlydiagnosisisessential.
A – asymmetry
B – border
C – colour– lightbrownisacceptable,anyothercolourisnot (pinkblue andwhite are the worst
colours).Irregularpigmentation.
D – diameter– upto 6mm isok
E – evolution –change?Pain?Bleeding?Oozing? Satellite nodules?Ulceration?
Otheradverse prognosticindicators
• Ulcerationisa strong adverse indicator
• Suffix bindicatestumourulceratione.g.pT3bisa tumourbetween2-4mmwithulceration –
ulcerationjumpsupa stage and survival rate decreases. a = notulcerated(e.g.pT1a)
• Highmitoticrate,lymphovascularinvasion,satellites,sentinellymphnode involvement
• Satellite depositsof melanomainskin=advancedmetastatic disease –verydifficulttomanage,
palliativecare
Four maintypesof melanoma:
• Superficial spreading (SSM) –trunksof menand legsof womenare the most commonareas.
Most commonsubtype,affectsyoung/middleagedadults. Usuallymaculewithirregularborder
and colourwhichmayhave beenincreasinginsize foryears(slow horizontal growthphase)
before developinganodule (rapidvertical growthphase).
• Acral/mucosal lentiginous-acral andmucosal (A/MLM) – palms,soles,nails andmucosal sites.
Usually inelderlypatients.Hutchinsonsign –pigmentedextensionintothe nail fold
• Lentigomaligna-sun-damagedface/neck/scalp (LMM) – elderlyface usually.Neoplastic
melanocytesalongthe basal layerwhichmaythenbecome invasive
• Nodular- variedsitesbutoftentrunk
• Notmain subtype - Amelanocyticmelanoma–Absentorminimal visible pigment.Rare.

2. SkinCancer
W3 L1 & 5
SSM, A/MLM and LMM:
- Grow as maculeswheneitherin-ituorwithdermal microinvasion(radialgrowthphase)
- Eventuallythe melanomacellsinvade the dermisforminganexpansile masswithmitoses
(vertical growthphase)
- Onlymelanomaswithavertical growthphase canmetastasise
Nodularmelanoma:
- No clinical ormicroscopicevidence of RGP
- A nodule of VGPtumour
- Some considerthismore aggressive
- Occurs at any bodysite
- Usuallyinolderpatients
- Blue-blackorred-skin-colourednodule whichmaybe ulceratedorbleedingandhasusually
developedrapidlyoverprecedingmonths
- Unlike nodulesdevelopinginsuperficial spreadingmelanoma,nodularmelanomasdonot
have any significantsurroundingmacularpigmentation
MM spread
- Local dermal lymphatics satellite depositsof MM – verybad prognosticsign
- Regional lymphnode metastases –commonpatternof disease progression. Nodesexcised
(radical lymphadenectomy)
- Bloodspread - Skin/ softtissue,Heart, Lungs,GI tract, liver,brain
MM treatment:
• Primaryexcisiontogive clearmargins
• Narrowcomplete excisionforconfirmationof diagnosisandassessmentof Breslow
• If in-situthenclearbycirca 5mm
• If invasive but<1mm thick -1cm clearance
• If invasive and>1mm thick -2cm clearance
• SNB if >1mm thickor thinnerwithmitoses
• Some alsoreceive asentinel nodebiopsy
• Sentinel lymphnode biopsycanprovide furtherprognosticinformation. If SN positive-
regional lymphadenectomy
• Treatmentof advanceddisease difficult
• Chemo,immunotherapy,genetictherapies
Melanomagenetics
Some acral melanomashave c-kitmutationsandmaybe treatedwithimantinib
Melanomasonintermittentlysun-exposedskinmayhave BRAFmutation
- Wildtype BRAFis a weakcytosolicproto-oncogene
- If mutateddrivescell proliferationbyup-regulatingMEKand ERK
- Range of drugsdevelopedtointerferewiththispathwaye.g.dabrafenibandvemurafenib
- Response timesare limited(onlyworksforabout6 months)
- May be betterincombinationwithMEKinhibitor
- May be betterinadjuvantsettingforhighrisklesionsbefore metastasesdevelop
- Rapidlyevolvingarea

3. SkinCancer
W3 L1 & 5
Non-melanoma skin cancer – Basal cell and squamous cell
• 90-95% of skincancers & Commonesthumancancer
• >100,000 cases peryearin UK & ~500 deaths/year
Basal Cell Carcinoma (BCC)
Clinical Presentation
- ~ 75% of NMSCs;verycommon – increasinglyseenin
youngerpatients
- Basal cellssproutfromepidermisandgroupsof cells
invade/budintodermis
- Mitosesandapoptosisverynumerous
- slowgrowinglumpornon-healingulcer–nodular,
superficial or ulcerated/infiltrative BCC
- painlessandoftenignored
- ‘pearly’ortranslucentbutcan be pigmentedBCC
- visible,arborisingbloodvessels
- central ulceration - “rodentulcer”
- can presentasscaly plaque - ‘superficial BCC’
- can be infiltrative- ‘morphoeicBCC’ – tumourcellsdosubclinical therefore are hardtotreat
- locallyinvasive,butrarelymetastasize40 yrs,but can be 3rd or 4th decade
- Margins are poorlydefinedandmayspreadalongnerves
- Can damage bonesof face or eyesif too close – resectionischallenging
- May kill byinvadingeye  brain–veryhard to treat/cure
Squamous Cell Carcinoma
Clinical Presentation
- about20% of all skincancers
- hyperkeratotic(crusted) orwarty lumpor non-
healingulcer
- arisesonsun-damagedskin
- grow relativelyfast,maybe painful &/orbleed
– feel lumptodiagnose
- majority- well differentiatedlowriskSCC –best
prognosis
- minority - poorlydifferentiatedhighriskSCC –
worstprognosis
- Ear, face,lipand scalpare highrisksites
- Perineural spreadisanadverse prognostic
indicator
- Precursors:Bowen’sdisease (esp.onlegs),
Actinickeratosis(esp.onhead/neck),Viral lesions(esp.onanogenitalskin).These precursorsshow
squamousdysplasia
- NotuncommoninUK forSCC to grow onchronic ulcers/scars/wounds
- Rare associationswith xerodermapigmentosumanddystrophicvariantepidermolysisbullosa

4. SkinCancer
W3 L1 & 5
- riskof metastasisabout5% - seriousconsequences
- poor prognosisonce metastatic
- Keratoacanthoma(KA) - self-resolving(notmalignantbutlookslikeSCC – remove tobe sure)
- 50% furtherNMSCat 5 years
- 5 yearsurvival rate of metastaticSCC25%
Actinickeratoses–pre-cancerousskinlesions,highlyassociatedwithincreasedriskof SCCor BCC.
Oftenmultiplegiving“fielddamage”ormore severe “fieldcancerisation”.
Potentially pre-malignant cutaneous tumours:
Actinickeratosis:
- Developlaterinlife inwhite-skinnedpeoplewhohave hadsignificantsunexposure
- Appearonsun exposedareas
- Erythematoussilver-scalypapulesorpatcheswithaconical surface and redbase
- Backgroundskin isofteninelastic,wrinkledandmayshow flatbrownmacules(solar
lentigos) reflectingdiffuse solardamage
- Small proportioncantransforminSCC but onlyaftermanyyears
- Tx – cryotherapy,topical 5-fluoroacill cream, 5% imiquimodcreamordiclofenacgel
Bowen’sdisease
- Intraepidermalcarcinomain-situ
- Rarelybecomesinvasive
- Due to longterm sunexposure andpresentsonsunexposedareas,mostcommonly
womenslegs
- No maturationof cellsleadstoparakeratosisonsurface
- Isolatedscalyredpatchor plaque lookinglike psoriasisbutithas an irregularedge
- Slowlyincrease withtimebutnodermal invasion
- Tx – cryotherapy,topical 5-fluoroacill cream, 5% imiquimodcream, cryotherapy,curettage
Actinickeratosis
- Verycommon
- Sun-exposedskinesp.scalp,face,hands
- Variable epidermal dysplasia
- Severelyatypical lesionsare bowenoid(lookslike
bowensdisease)
- Commonprecursorof invasive SCC
Atypical/Dysplasticnaevussyndrome –see W3 L3&4 notes
Giant congenital melanocyticnaevi - see W3L3&4 notes
Viral precursors
- Viral genital lesionsoftendysplastic withelevatedatypical mitoses
- Erythroplasiaof Queryat= penile Bowen’s
- AssociatedwithHumanpapillomavirus - HPVtype 16 associatedwithdysplasia
- HPV in almost100% penile dysplasia.HPV foundin50% invasive penileSCC

5. SkinCancer
W3 L1 & 5
Risk factors for skin cancer
- Sunexposure (espUVA)
o Sunburnandsolar lentigo(liverspots,oldage spots) reflectUVBdamage,whereassolarageing
isattributedtothe deeperpenetrationandsolar elastosisof UVA.
o The formationof ‘sunburn’cellsisaprotective mechanismwherebybadlyUV-damaged
keratinocytesundergoapoptosisorprogrammedcell death.Frecklesoccurinthose who
cannot tan sufficientlytoprotecttheirskinfromsun.
o Damage occurs repeatedlyleadingtoDNA mutationsandskincanceroccurs
o Up to 80% sun damage occurs duringfirst18 years
o Childhoodsunburnincreasesmelanomarisk4x
o SCC - chronic,cumulative UV-exposure(total exposureisthe mostimportantfactor,
irrespectiveof howitisachieved)
o BCC - intermittent,intensesunburnepisodes
o Melanoma- intermittent,intensesunburnepisodes
o Those whowork outdoors(farmers,sailorsetc) are at increasedriskastheyare constantly
exposingtheirbodiestothe sun.
- Geneticsusceptibility
o Amountandtype of melanindictatesyouskintype (SPT1-4)
o DNA repairsyndromes,e.g.XerodermaPigmentosum –defectinone of 7 nucleotide
excisionrepairgenesleadingtophotosensitivity,skincancersonUV-exposedsites,
neurological degenerationandincreasedriskof othercancers
o Albinism
o Naevoidbasal cell carcinoma(Gorlin’s) syndrome –autosomadominantfamilial cancer
syndrome – earlyonset/multiple BCCs.Palmerpitsjaw cystsandectopiccalcificationfalx
- Immunosuppression –SCC isthe most commonformof skincancerin these patients.Organ
transplantrecipientsneedregularskinsurveillance.
- Otherenvironmental carcinogens:coal tar,smoking,ionisingradiation,arsenic,trauma,chronic
ulceration
Phototoxic drugs:
- Voriconazole Thiazide diuretics
- Anti-TNF NSAIDs
- BRAFinhibitors
Skin cancer prevention
Behaviour:
- avoidsunat its height(11am-3pm)
- use shade whereverpossible
- particularcare of babies/children
avoidsunbeds
Sunscreens- broadspectrum(SPF25+)
withUVA protection
Clothing
- tightlywoven,loose fittingclothing
(dark)
- longsleeves,trousers,skirts
Regular (self-) surveillance
Examine molesregularlyandif in
doubt“check itout”
Sun Smart
S – Stay inthe shade 11am-3pm
M – Make sure youneverburn
A – Alwayscoverup
R – Remembertotake extracare with
children
T – Thenuse factor 15+ sunscreen

6. SkinCancer
W3 L1 & 5