MEDI7305 Lecture Notes - Lecture 1: Paresthesia, Hemoglobin, Spitz
M1a - Skin Lesions in Rural Setting
Learning objectives
Skin lesion History, exam and 'skin check'
Description - site, size, appearance
Dermatoscopy Asymmetry, colour, structure, networks, dermatoscopic checklists
Benign vs
malignant (rural
setting)
Benign skin lesions Malignant skin lesions For each skin lesion …
Freckles -
ephelides, lentigines
Moles -
benign melanocytic naevi
Atypical/
dysplastic naevi
Seborrheic
keratoses
Dermatofibr
omas
Solar
keratoses
Sebaceous
hyperplasia
Cherry
angiomas
Warts
Skin tags/
acrochordons
Pyogenic
granulomas
Chondroder
matitis nodularis helicis
Malignant melanoma
- melanotic and amelanotic
Superficial
spreading
Nodular
Lentigo
maligna
Acral
lentiginous
Desmoplastic
/ neurotropic)
Non-melanoma skin
cancer (NMSC)
Basal cell
carcinoma (nodular,
superficial, morphoeic,
pigmented)
Squamous
cell carcinoma
(keratoacanthoma, Bowen's
disease)
Epidemiolog
y
Risk factors
Typical
appearance + body site
affected
Macroscopic
clinical features
Dermatosco
pic features
Definitive
diagnosis
Managemen
t options
Prognosis
Follow up
Procedures Shave vs punch vs excision biopsy
Cryotherapy
Curettage
Topical therapies (5-FU, diclofenac, imiquimod, photo dynamic therapy)
Radiotherapy
Key points
Red flags - new, pink, black, multi-coloured, bleeding, growing or changing lesions
Skin lesion workup
Macroscopic - ABCDE/ EFG/ 'ugly duckling'
Dermoscopic
Excision margins
Suspected melanomas require 2mm excision margin
Suspected BCCs and SCCs can be biopsied if diagnosis is uncertain
Definitive malignant skin lesion
o5mm for proven melanoma in situ
o4mm for most SCCs
o3mm for most BCCs
Malignant melanoma
Australian
epidemiology
Australia has the world's highest incidence of melanoma
2011 (1544 deaths from melanoma), 2010 (11,405 cases of melanoma)
Gender
Men - 4th most common cancer diagnosis (after prostate, bowel and NMSC) & 6th
most common cause of cancer death
Women - 4th most common cancer diagnosis (after breast, bowel and NMSC) & 10th
most common cause of cancer death
Men are 2.5x more likely to die of melanoma than women
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Age
1 in 17 people diagnosed by age 85
o1 in 14 men diagnosed by age 85
o1 in 24 women diagnosed by age 85
Most common cancer in people aged 15-39yo
o20% cancers, 8% cancer related deaths
Types
Risk factors Calculate 5-year melanoma risk with online calculator (low, moderate, high)
Age [increasing]
Gender [male]
Latitude [north]
# common naevi on arms
# atypical naevi on whole body
Freckles
Hair colour [redhead]
Personal hx of melanoma
Personal hx of non-melanoma skin cancer
Family hx of melanoma
Typical
appearance/
body site
Development
Arise de novo (75%) vs pre-existing mole (25%)
1/3 melanomas grow at 0.5+mm per month
Amelanotic melanomas grow 6x faster than melanotic
Breslow thickness
oMelanoma in situ - 5mm margins is curative
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find more resources at oneclass.com
o1mm thick - 91-95% 5ysr
o3mm thick - 63-79% 5ysr
o5mm thick - 45-67 5ysr
oMetastatic - 5-20% 5ysr
Most distant mets occur in lung, liver, brain, bone
Body site
Most common is trunk (men) or legs (women)
Commonly skin, sometimes nails/ eyes/ lips/ mouth, rarely intraocular/ intrauveal/
urogenital tract/ gastrointestinal tract
Clinical
features
ABCDEs
Nodular melanoma -
evolves over weeks to months
Superficial spreading
melanoma - evolves over months to
years
Lentigo maligna
melanomas - evolves over years to
decades
EFG
Nodular melanomas
don't follow ABCD rule (symmetrical,
regular border, one colour, small)
Be suspicious of lesion
appearing like 'blood blister' or
'pimple' arising from uninjured,
lesion-free skin
Elevated
Firm
Growing over
weeks
Ugly duckling
A lesion noticeably
different from the rest of a person's
moles
Prognostic
factors
5 main prognostic factors
Breslow thickness (depth of melanoma invasion (mm))
Most important factor for predicting disease progression
Thickness is defined as distance from the top -> deepest invasive cells across base
oUlcerated - the top is the base of the ulcer
oNon-ulcerated - the top is the granular layer of epidermis
Thinner is a more favourable
T stage (TMN) Breslow thickness Surgical margins Risk of met spread to regional
LN
Tis In situ 5mm 0%
T1 <1mm 1cm 5-10%
T2 1-2mm 1cm 15-25%
T3 2-4mm 2cm 15-25%
T4 4+mm 2cm 25-40%
Ulceration
Absent is more favourable
Mitotic rate per mm2
Lower number is more favourable
Lymph node status at diagnosis
Absence of LNs is more favourable
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Topical therapies (5-fu, diclofenac, imiquimod, photo dynamic therapy) Red flags - new, pink, black, multi-coloured, bleeding, growing or changing lesions. Suspected bccs and sccs can be biopsied if diagnosis is uncertain. Australia has the world"s highest incidence of melanoma. 2011 (1544 deaths from melanoma), 2010 (11,405 cases of melanoma) Men - 4th most common cancer diagnosis (after prostate, bowel and nmsc) & 6th most common cause of cancer death. Women - 4th most common cancer diagnosis (after breast, bowel and nmsc) & 10th most common cause of cancer death. Men are 2. 5x more likely to die of melanoma than women. 1 in 17 people diagnosed by age 85. 1 in 14 men diagnosed by age 85. 1 in 24 women diagnosed by age 85. Calculate 5-year melanoma risk with online calculator (low, moderate, high) Arise de novo (75%) vs pre-existing mole (25%) Melanoma in situ - 5mm margins is curative o o o o.
