Melanoma

Melanoma ismalignant tumourmelanocytes. Melanocytes predominantly occur inskin but can be found elsewhere, especiallyeye. The vast majoritymelanomas originate fromskin.

Tablecontents

1 Causation 2 Behaviour 3 Typesmelanoma 4 Symptoms 5 Treatment

Causation

Solar radiation ismajor causative factor andriskrelated to:

• The degreesolar exposure.
• The age at which solar exposure occurs
• Natural skin pigmentation.

Exposure during childhood ismore important risk factor than exposureadulthood. (Thisseenmigration studiesAustralia where people tendretainrisk profiletheir countrybirth ifmigrateAustralia as an adult). Fairred-headed peopleat greater risk.

Other risk factors include"Dysplastic naevus syndrome" which isfamilial conditionatypical moles carryinglowmoderate riskacquiring melanoma.

Behaviour

Features that affect prognosistumor thicknessmm (Breslow depth), depth relatedskin structures (Clarke), typemelanoma, presenceulceration, presencesatellite lesions,presenceregional or distant metastasis.

With regardtumor thickness attimediagnosis: thin melanomas (<0.75mm) havegood prognosis, i.e.can usually be cured by surgical excision alone; tumorsmore than 4 mm thickness attimediagnosisvery often metastaticcan show very aggressive growth.

Typesmelanoma

• Superficial spreading (often fairly thin).
• Nodular (often deeper)
• Acral lentiginous (on solespalms).
• Hutchinsons melanotic freckle (oftenolder patients).

Symptoms

Diagnosismelanoma requires expert knowledge, as early stages may look identicalharmless moles. Signssymtoms melanoma include:

• darkly pigmented skin lesion, sometimesareaslittle pigmentation
• irregularly shaped skin lesion
• growth or changeshape
• itching, ulceration or bleeding

Treatment

Surgical excison - usually curativethin lesions. Immunotherapytolesser extent chemotherapy may havesomewhat experimental roleadvanced tumours.