Table of contents
- 1. Intro
- 1.1. Sun Protection
- 2. Melasma
- 3. Actinic Keratosis
- 4. Non-Melanoma Skin Cancer
- 4.1. Risk Factors
- 4.2. Treatment
- 4.3. Basal Cell Carcinoma
- 4.3.1. Noduloulcerative BCC
- 4.3.2. Superficial Multicentric BCC
- 4.3.3. Morpheaform / Sclerosing BCC
- 4.3.4. Pigmented BCC
- 4.4. Squamous Cell Carcinoma
- 5. Melanoma
- 5.1. Risk Factors
- 5.2. Dysplastic nevi
- 5.3. Types of Nevi
Intro
- UVB - Burning, sunburn, delayed tanning, aging and skin cancer
- UVA - Aging, penetrates deeper, not as intense, penetrates through window glass, immediate and persistent pigment darkening, skin cancers
- Melanoma >68,000 cases/year
- 1/7 risk of skin cancer
- 1/62 risk of melanoma
Sun Protection
- SPF = Sun Protection Factor = TimeToBurnWithSunscreen / TimeToBurnWithoutSunscreen
- SPF15 cover 93% of UV
- Apply 15-30min before exposure, apply liberally
- Kids
- Keep out of sun 10-4pm
- Hats, tightly woven clothing
- Sunscreens >6mo
- Careful of water, sand, snow, concrete (reflects UV)
- Clouds: allow up to 80% of UVB
Melasma
- Strict sun avoidance
- Bleaching creamsHydroquinone
- Lustra
- Ultraquin
- Neostrata HQ
- Stop OCP
Actinic Keratosis
- Most common pre-malignant skin lesion
- Arises from cumulative effect of UV exposure
- 5-20% of pts develop malignancy
- 0.25-1% of AK convert to SCC/year
- 60% of new SCC in site of previous AK
- Well-circumscribed erythematous base with adherent scale (tacked-on appearance)...often easier to feel than see.
- Flesh colored or pigmented.
- Usually multiple
- Superficial - little or no invasion
Non-Melanoma Skin Cancer
Risk Factors
- External: UV, radiation, immunosuppression
- Immunosuppression is huge: 50% develop skin cancer in 20yrs post-transplant, 1 in 4 heart transplant patients die of skin cancer in Australia.
- Genodermatoses
- Albinism
- Xeroderma pigmentosum
- "Nevoid BCC Gorlin Syndrome"
- SCC precursor lesions (AK, SCC in situ)
- Chronic Skin Disorders (SCC only)
- HPV
- Burns, Scars, Ulcers
Treatment
- Topical (limited efficacy) - 5-FU, Imiquimod
- Destructive (no histologic margin confirmation)
- Scraping --> Curettage
- Burning --> Electrosugery, laser
- Freezing --> Cryotherapy
- Photochemical --> Photodynamic therapy
- Irradiating --> Rads
- Sugery
- Standard excision
- Mohs micrographic excision (taking slices and looking under microscope until margins clear) - minimally invasive, cosmeticaly pleasing.
Basal Cell Carcinoma
- 11-33% lifetime risk, usually >40yo, 86% occur on H&N, usually nose
- Types:
- Noduloulcerative (50%-54%)
- Superficial (9-11%)
- Pigmented (6%)
- Morpheaform (2%)
- Basosquamous (1%)
- Almost never metastasis
Noduloulcerative BCC
- Most common
- Single
- Nodular, smooth, pearly well defined border, telangiectasia, can ulcerate & crust
- Hx: pimple-like lesion that bleeds and does not heal.
Superficial Multicentric BCC
- Often with actinic damage
- Usually on trunk
- Lightly pigmented, erythematous & patch like
- Eczema & psoriasis
Morpheaform / Sclerosing BCC
- Indurated yellow-white sclerotic plaque w/ ill defined borders
- Often difficult to see, palpation reveals indurated mass
Pigmented BCC
- Clinical features & behavour similar to noduloulcerative
- Brown pigmentation with rolled pearly borders - often mistaken for melanoma
Squamous Cell Carcinoma
Bowen's Disease: Intraepithelial SCC
- Aka carcinoma in-situ
- Older pts, solitary, sun & non-sun exposed areas
- Well demarcated, irregular borders, erythematous & scaly plaque
- May be pruritic, crust & bleed
- 3-5% become SCC
- Tx:
- Adequate excision
- Topical therapy if multiple lesions
Squamous Cell Carcinoma
- Two types:
- Actinically induced SCC
- more cmmon
- Solar etiology - occur in sun exposed areas & areas of actinic damage
- low incidence of metastatsis (<1%)
- De novo SCC
- Associated with non-solar etiology
- Higher metastatic rate (~10-30%)
- Presentation
- Usual Presentation: Thick & Scaly hyperkeratotic plaque, ulcerated base when crust removed.
- Other Presentations: Persistent ulcer, pigmented
Melanoma
Risk Factors
- Light Complexion - hair, eyes, skin
- Lots of nevi (moles)
- Dysplastic nevi
- Congenital nevi
- Family hx of melanoma
- Excessive sun exposure
Dysplastic nevi
- Irregular "hazy" margin
- Asymmetric
- Irregular colour, very dark, or mixed in color
- Usually >6mm
Types of Nevi
Junctional Nevi
Compound Nevi
Intradermal Nevi
Blue Nevus
Halo Nevus
Comments