NZ has one of highest rates of melanoma in teh world

most common cancer NZ men 25-44yo

11% of all cancer registrations

tenth most common cause of death from cancer

mortality invasive melanoma = 15%

males > females

mortality 90% higher cf. females

Melanoma = type of skin cnacner that develops from melanocytes

• normally located in basal layer of epidermis or whitin dermis

• may develop wihin existing melanocytic naevus

• more often arises in normal skin

Maori/Pacific

• signifiantly less common

• 2.7/100 000 people /year

• present with thicker lesions

Melanocytic naevus

• benign proliferation of melanocytes

• Most euro NZers have 20-50 moles

• congential/acquired

• Development of new mole >50yo less common

Atypical naevus/Clark’s naevus

• melanocytic naevus

  • unusual in appearacne

• Most develop during childhood

• >5 = higher risk of melanoma

• atypical =

  • size >5-6mm

  • Border htat is blurry or ill-defined

  • unusual irregular shape

  • variation in colour

  • variation in profile i.e. flat and rasied parts

Risk factors for melanoma:

• Age:

  • >60yo

  • older men - thicker lesions

  • 1-2% in children - thicker lesions

• Past history of skin cancer (inc. non-melanoma)

  • melanoma = 10x increase developing another melanoma

  • non melanoma = 4x

• Family history o fmelanoma

  • first degree = 2x

  • 10% of people with melanoma have family hisotry of melanoma in first degree relative

• Number of moles

  • number of melanocytic naevi increases: esp if >100

• Type of mole

  • atypical naevi

    • 6x inc if >5

• UV radiation

  • UVB/UVA or UVA from sunbed

• Skin type

• Changeable weather:

  • intermittent cf. constant: sunseeking behaviour

Types of melanoma

• 10% are non-pigmented

• Superficial spreading melanoma

• most common

• sun exposed parts of body

• flat patch that is irregularly shaped

• irregularly pigmented

• irregular outline

• porlonged pre-invasive in-situ phase

• Nodular melanoma

• 2nd most common type

• rapidly growing

  • over several wekes to months

• pink, red, brown or black nodule

• pigmentation more uniform cf. SSM

• may arise within existing melanocytic naevus or in normal appearing skin

• more likely to bleed/ulcerate

• doesn’t have in-situ phase

• EFG(elevated, firm and growing)

• Lentigo maligna melanoma

• sundamaged skin in older people

• long pre-invasive insitu stage - years to decades

• enlarging irregularly pigmented freckle

• Acra lentiginous melanoma

• palms, soles, underneath finger/toe nails

• 5% melanomas

• most common in dark-skinned

• may not demonstrate characteristic associetated with melanoma at other body sites

• Mucosal lentiginous melanoma

• arise from mucosal or paramucosal sites

  • vulva, vagina, anus, penis, eyelids, conjunctiva, oral cavity, lips

Toenails/subungla melanoma

• longitudinal melanoychia (brown/black stripe throughout full length of nail)

• skin surrounding nail folds may be involved

• most comon = subungal haematoma

ABCDE checklist

• Asymmetry

• Border irregularilty

  • notched

  • blurred

  • ragged edges

• Colour variegation

  • different colours

    • brown,black,white,red,blue

• Dianmeter >6mm

• Evolution or enlargement

• not very specific

Glasgow seven point checklist

• Major (2 points)

  • change in size

  • change in shape

  • change in colour

• Minor (1 point)

  • inflammation

  • crusting, oozing, bleeding

  • sensory change/itch

  • Lesion diameter >= 6mm

• excision if >3 points or more

Mole mapping

• Mole mapping most useful in patients with a large number of moles, atypical naevi, oles on back that are hard to see and those at high risk ok melanoma

• advantages:

  • rapid

  • lesions of concern are detected early - allowing careful follow-up

  • unnecessary excisions may be reduced

  • access to mole mapping quicker/easier than access to dermatologist

• disadvantages

  • scalp/genitals may be missed

  • false negatives

  • false positives

  • interval b/w molemapping appt may be too long for rapidly growing lesions

  • Cost (\~300$)

Feet

• CUBED acronym

  • coloured lesions where any part is not skin coloured

  • uncertain diagnosis

  • bleedinglesions on foot or under nail

    • including chronic granulation tissue

  • Enlargement or deterioration of lesion or ulcer despite treatmnet

  • Delay in healing (>2months)

• difficult to determine cuase of subungual bleeding

Excision:

in situ (pTis) : 5mm margin

pT1 \<1mm: 1cm

>1mm = refer

pT2-pT3 1-4mm: 1-2cm

pT4 >4mm: 2cm

sentinal node biopsy discuss with patients who have a primary tumour 1.2-3.5mm thick

genetic testing not worthwhile

CLark’s Level

1. Melanoma confiend to epidermis

2. Invasion into papillary dermis

3. Invasion to junction of papillary and reticular dermis

4. Invasion into reticular dermis

5. Invasion into subcutaneous fat

Breslow thickness

• measurement in mm thickness of melanoma = depth of penetration

• \<1mm lower risk