DERM - Skin cancer Flashcards
What are the worrying symptoms and signs of a potentially malignant lesion
Clues to melanoma:
• overall pattern recognition or the ‘ugly duckling’ sign rather than formal diagnostic criteria
•New lesion
•A history of CHANGE in a naevus is concerning
describe the epidemiology and anatomical distribution of NMSC and melanoma
Non-melanoma skin cancers (98%) •BCC (67%), SCC (31%) •Most common Cancer •Common, usually not life threatening •400 deaths per year (Mainly SCC)
Melanomas
(2%)
•Less common, more dangerous
•4th most common Cancer in Australia, highest rate
•Melanomas have the potential to spread internally to the lymph nodes and internal organs
•1500 deaths in Australia in 2011
The incidence of treated BCC and SCC is > 5x the combined incidence of all other cancers combined.
Where may SCC arise from?
a group of disorders characterised by keratinocyte dysplasia:
–Actinic keratosis
–SCC in situ (Bowen’s disease)
–SCC
What do melanomas arise from?
melanocytes
Describe SCC (Squamous cell carcinoma)
- appearance
- common sites
- SCC less common but more dangerous than basal cell carcinomas.
- Rapid rate of growth, over weeks or months, greater potential to metastasize to regional lymph nodes and distant sites –Urgent assessment required
- Usually present as a thickened scaly red patch or nodule, which may bleed easily or ulcerate and may be tender.
Common sites:
chronically sun-exposed sites; hands, forearms, head, ears, lower lip and neck.
Rx of SCC
Complete surgical excision with clear margins
High risk lesions may require additional adjunctive management eg radiotherapy
–Radiotherapy may be used alone if clinically warranted- eg elderly, surgical risks, size of defect
Describe BCC (basal cell carcinoma)
- characteristic of disease
- appearance
- common sites
- how Dx
- red flag
Common; 2/3 of all skin cancers in Oz. Locally invasive but very rare to metastasise. more indolent/slower growth than SCC
- PEARLY nodule with central ulceration measuring about 5mm in diameter
- Telangiectasia across the lesion
- chronically exposed to the sun; head and neck > trunk > limbs.
Confirm the diagnosis with a biopsy
Red Flag: Bleeding is an important clue for the diagnosis of BCC
What can nodular BCC mimic?
Melanoma if pigmented
Describe superficial BCC (SBCC)
- appearance
- red flag
Superficially invasive
- Presents as slowly enlarging plaque
- May develop superficial erosion
- Red Flag: Beware the solitary red plaque not responding to topical treatment
Rx of BCC
•Nodular or Infiltrating: Surgical excision with clear margins
Superficial BCCs •Surgical excision •Serial Curettage •Topical Imiquimod •Photodynamic Therapy (PDT)
Describe actinic keratoses (solar keratoses)
- characteristic of disease
- appearance
- common sites
- Red flag
Very common w/ age. Can progress to invasive SCC but rare.
- Erythematous scaly lesions on dorsum of hands
- Not indurated nor tender
Sites: Sun exposed skin on the face, scalp, forearms and dorsum of hands
Red Flag: Beware of the growing hyperkeratotic and tender nodule amongst the AKs – this could be a sign of malignant transformation into SCC
Rx of actinic keratoses
–Cryotherapy
–Topical: 5-FU, Imiquimod, Ingenol mebutate, diclofenac in hyaluronic acid, PDT
–Surgical excision for lesions which are
•resistant to treatment or
•suspicious for SCC
Describe Bowen’s disease (in situ SCC)
- characteristic of disease
- appearance
- common sites
A type of keratinocyte dysplasia.
•It is a SCC in situ, where full thickness epidermal dysplasia is seen, but it is non invasive
•The risk of malignant transformation into SCC is estimated at 3-5%.
•These lesions are often asymptomatic, but can be itchy, painful or may bleed.
Common sites: sun exposed areas, esp lower limbs.
Rx of Bowen’s disease
–Topical
•5-FU, Imiquimod, PDT
–Surgical excision for lesions which are
•resistant to treatment or
•suspicious for SCC
•certain high risk patient groups
Examples of pigmented lesions
•Lesions of melanocytes
–Benign naevi
–Malignant melanoma
•Also, some lesions which look pigmented, but are not melanocytic in origin
–Eg pigmented BCC, pigmented actinic keratosis, seborrhoeic keratoses, solar lentigines- due to melanin or keratin
Describe characteristics of benign moles
- Tend to be small
- Evenly coloured
- Regular edges
- 1 colour
- Symmetrical
- Does not “stand out”
- Does not change with time
Describe pigmented solar keratoses
- Middle-aged people
- Sun-induced
- Usually scaly and erythematous, but can be pigmented
- Rough surface
Describe characteristics of dysplastic naevi
- size
- colours
- borders
- what is it an independent risk factor for?
- Naevi which show atypical features both clinically and histologically but are not malignant melanoma
- Larger (>5mm)
- Atypical pigment net on dermoscopy
- 2 or more colours
- Smudgy borders
- Generally still symmetrical
Independent risk factor for development of melanoma, especially if several
There is no place for the prophylactic excision of dysplastic naevi but if melanoma suspected, it should be excised urgently
What are (11) risk factors for melanoma?
–Multiple dysplastic naevi (more than 5)
–Multiple (>100) typical naevi
–Past history of melanoma
–Strong family history (1 or more first degree family members)
–History of blistering sunburns (esp. childhood)
–Previous non-melanoma skin cancer
–Type 1 skin (burns easily with no tanning)
–Freckling
–Blue eyes
–Red hair
–Immunosuppression
Common sites of melanoma distribution in women & men
Women: legs
Men: trunk, head & neck
Px of melanoma
A - Asymmetry B - Border irregularity C - Colour variegation D - Diameter (>5 mm) E - Evolution (any changing lesion)
N.B: some subtypes of melanoma do not fulfil these criteria & Many benign lesions may satisfy all the ABCDE criteria (e.g. seborrhoeic keratoses or dysplastic naevi)
What are (4) melanoma subtypes?
- Superficial spreading melanoma (SSM): 80% of melanomas. Usually follow the ABCDE rules. Evolves over weeks to months
- Lentigo maligna: very slow evolution.
- Acral lentiginous melanoma
- Nodular melanoma: often do not fulfil ABCDE criteria. Rapid growth & early invasion. Common in older males (less doctor visit). Follow an EFG rule
How do nodular melanomas present?
EFG (rather than ABCDE)
•Elevated
•Firm
•Growing
If in doubt, excise completely and urgently
Describe (2) biopsy techniques in skin cancer
- what are they recommended for
- Partial biopsies (not recommended for pigmented lesions – sampling error)
•Punch biopsy (2-3mm biopsy punch into lesion)
•Shave biopsy (shave across lesion into dermis. Not good for assessing depth of lesion) - Excisional biopsies (best for pigmented lesions)
Punch biopsy & shave biopsy are appropriate Ix to confirm the diagnosis of NMSC but be aware of limitations
What determines the excision margins for melanoma?
Breslow thickness
E.g.
- in situ thckness -> 5mm margin
- 1cm margin etc
Prognosis of melanoma
Survival depends on the depth
- In situ: 100%
- 4mm: 45-67%
Other factors determining prognosis:
–Ulceration, mitotic rate
–Age, sex, other patient factors
–Location
Advise on sunprotection
- SLIP on a shirt
- SLOP on some sunscreen
- SLAP on a hat
- SEEK shade
- SLIDE on some sunglasses…
