PIGMENTED SKIN
LESIONS Richard Shellenberger, DO, FACP
IT’S NOT A SPIDER BITE
PART 2
No financial disclosures
Not Spider Bites!
Not in Michigan!
“Spiders do not bite”
• Chris Buddle – Arthropodologist – McGill University,
Montreal, Canada
• Never been bitten in 20 yrs of handling spiders
• “Have to work hard to get a spider to bite you”
Why dermatology? Important in IM
• “I have no special talents. I am only passionately curious”
Albert Einstein
• “Develop a passion for learning. If you do; you will never
cease to grow.”
Anthony J D’Angelo
• “There is no passion to be found in playing small – in
settling for a life that is less than the one you are capable
of living.”
Nelson Mandela
Goals
• Improve comfort with office dermatology
• Learn to identify and risk stratify pigmented lesions
• Excise suspicious lesions or call someone who can!
• Skin cancer prevention and awareness
• (please read my commentary in JFMPC)
Acrodhordon (skin tag)
Outgrowths in middle aged and elderly, F > M
• Pedunculated lesions - narrow stalks
• 25% of adults with familial tendency
• Friction areas – Neck, axilla, breasts are more
common with obesity
• Treatment : Excision or liquid nitrogen PRN
Cherry Angioma
• Capillary proliferations in middle aged – elderly
• On trunk
• Bleed!
• Can be confused with amelanotic or nodular melanoma
• Electrocauterize or excise
Dermatofibroma
• Fibroblastic proliferation
• Firm, hyperpigmented, dome shaped nodules on leg
• Dimple sign when pinched
• Nodular BSC are waxy and have telangectasias
• Remove only if change
Pyogenic Granuloma
• Not an infection……or spider bite!
• Rapidly developing hemangioma – capillary
proliferation
• Site of trauma
• Erythematous, dome shaped, bleed easily
• Isolated lesions on fingers, lips trunk or toes
• Excision and ablate the base
Epidermoid Inclusion Cyst
• Traumatic implantation of epidermis
• Accumulation of keratin
• Enclosed in stratified epithelium
• Lipoma
• Excise or inject with steroids
Seborrheic Keratosis (SK)
• Develop after 50
• “Stuck on” appearance
• “Warty”, well circumscribed, scaly hyperpigmented lesions
• Trunk, face, and upper extremities
• Horny cysts and dark keratin plugs
Solar lentigo
• Proliferation of normal melanocytes
• Flat, oval, evenly pigmented (café au lait)
• Sun exposure
• Face, hands, arms, shoulders, and back
• Lentigo maligna
• variable pigment and irregular borders
• Lentigo maligna melanoma : raised nodule
Actinic Keratosis (AK)
• Rough appearing, scaly, erythematous papules
• Sun exposed areas of middle-aged with fair skin
• Michigan sailors and farmers (never in golfers!)
• Sandpaper
• Premalignant (~1/1000 > SCC)
• Treatment with cryotherapy
Nevus
• Melanocytic nevus
• Benign proliferation melanocytes in childhood
• Number peaks in early adulthood
• Types of nevi
• Junctional Nevi
• Flat pigmented macules on acral surfaces
• Melanocytes in dermal epidermal junction
Nevus
• Compound nevi
• Melanocytes in dermal-epidermal junction as
well as dermis
• Congenital Nevi
• Present at birth
• Giant congenital pigmented hairy nevus
• 20 cm diameter
• 3-6% may develop into melanoma
Becker’s Nevus
• Benign Hamartoma
• Adolescent
• M/F = 5:1
• Shoulder and trunk
• Tan - brown
Dysplastic Nevus Is it cancer?
- Asymmetry
- Borders – irregular
- Color – dark or variegated
- Diameter – size > 5 mm
- Evolving - any changes
Dysplastic Nevus
• Slightly elevated
• Central Papule surrounded by a Pigmented Macule
• Most commonly on trunk and back – same as melanoma
Dysplastic Nevus
• Epidemiology
• 7-16 % prevalence
• May evolve from normal appearing nevi
• May develop after age 30
• Sun exposure theorized:
• Intermittently sun exposed areas (trunk)
• History of sunburn
• Sun-sensitive skin types
Dysplastic nevus (DN)
• Clinical Significance (RISK OF MELANOMA)
• 15 X age-adjusted incidence of melanoma
• But only 1 in 10,000 DN per year progress to melanoma.
• Risk of melanoma = # of DN (10 DN = 12 x risk)
• First degree relatives should be screened for melanoma
Dysplastic Nevus and Melanoma
• 200 fold increase in melanoma if 2 family members with
melanoma
• Melanoma can arises contiguous to DN
• Histology of dysplasia NOT predictive of Melanoma
• # of DN most predictive
• ? evidence for clinical atypia being predictive
Dysplastic Nevi
• Controversial
• Sunscreen and avoiding sun exposure
• Not shown to decrease the development of DN
• Dermoscope
• Excision with 1-2 mm margin to r/o melanoma.
• Excision of dysplastic nevi does not reduce the risk of melanoma.
• Pt with multiple DN need increased surveillance
Halo Nevi
• Pigmented nevi with surrounding white halo due to
lymphocytes
• Mostly in adolescents
• Think melanoma when seen in adults and Excise them!
Halo Nevus
Skin Cancer
• Sunlight
• Pop quiz
• A farmer with lifelong sun exposure in his arms is most likely to get
what type of skin cancer?
• A. Melanoma
• B. Non-melanoma
• Lifetime risk all skin cancers is 1:5
• Melanoma is 2.4%
Sun Exposure
Melanomas arise in areas susceptible to sunburn
- Dark skin or those who tan easily are at lower risk of melanoma
- Intermittent exposure and sunburn in adolescence or childhood = risk
• Key #: 5 or more sunburns = 2x risk of melanoma
Sun Exposure
• Nonmelanoma skin cancer is associated with cumulative
sun exposure
• Melanoma = sporadic exposure except for head and neck
• Back and trunk in men
• Legs in women
• SUNBURNS = BAD
Skin Types
• Type I
• White skin, blue or hazel eyes
• Always burns and never tan
• Type II
• Fair Skin, blue eyes
• Burns easily – tans poorly
Skin Type
• Type III
• Dark white skin
• Tans after burning
• Type IV
• Light brown skin
• Minimal burning, tans easily
Skin Types
• Type V
• Brown Skin
• Rarely burns, tans easily
• Type VI
• Dark Brown Skin
• Never burns, tans easily
Nonmelanoma Skin Cancer
• Basal Cell Skin Cancer
• 60% of primary skin cancers
• Slow-growing locally invasive
• Recurrence after excision increases risk of metastasis
• Most common on face
Basal Cell Carcinoma
• Appearance
• First round oval
• Extends circumferentially
• Raised edges
• Shiny, pearly or translucent
Basal Cell Carcinoma
• Growing edges irregular and shape is uneven
• Central atrophy
• Hollow covered by vessels and ulceration
• Base invades underlying tissues
Squamous Cell Carcinoma
20 % of all cases of skin cancer
• Risks:
• Sun exposure
• Ionizing radiation
• Organic trivalent arsenic compounds
• Pipe smoking
• HPV
Squamous Cell Carcinoma
• Appearance
• Redness, slight scaling and fissuring initially
• Appears dry and may bleed when scratched
• Spreads laterally from edges and may heap up irregularly
• Centers may be atrophic and ulcerated
Keratacathoma
• Can be confused with SCC
• Occurs at trauma sites, esp immunocompromised
• Skin colored or pink initially and become dome shaped with rapid growth
• Matures to volcano shaped with protruding masses of keratin resembling lava.
• Will regress spontaneously!
Malignant Melanoma
• 1% of skin cancers but majority of deaths
• 76,000 annual cases in US (~10,000 deaths)
• #5 prevalence
• One of 3 cancers with mortality not decreasing in men
• Survival increasing – early diagnosis important
• 98% 5 yr survival if no LN involvement
• 63% if LN involvement
• 16% if organ involvement
Melanoma
•3X increase in incidence since 1975
• Lifetime risk in US 1:40 (2.4%) – mostly
whites
• 1:35 for men
• 1: 54 for women
• Yearly rate in Michigan > Texas and Florida
Melanoma
• Mortality increasing
• Only melanoma of top 7 US cancers increasing
• 31% have organ involvement at dx
• Mortality linked
• Thickness at time of dx
• Regional spread
• Physicians find melanoma earlier
• LOOK!
• Excisional Biopsy! – Early diagnosis!
Melanoma
• Screening, Counseling, Prevention
• Primary care can make a difference
• ABCDE’s
• Itching or bleeding – excise it!
• When in doubt – Take it Out
Superficial Spreading Melanoma
• Most common type of melanoma
• Dark brown or black
• Slowly spreading irregular outline
• Vertical growth late
Nodular Melanoma
• Shiny black dome – looks bad!!
• Grows vertically at the start and is more likely to
metastasize as grows more quickly
• Little or no lateral extension
Nodular Melanoma
Lentigo Maligna Melanoma
• Occurs in pre-existing lentigo maligna
• Appearance of nodules heralds change to invasive lesion
Acral Lentiginous Melanoma
• Palms, soles of feet, under nails, mucosa
• Least common melanoma
• Dark-skinned patients will get this type
Eponym for subungal melanoma?
Amelanotic melanoma
• Diagnosed later and prognosis worse
because lack of pigment
• Keys:
• sun exposure with sunburns
• moles that change: itch and bleed
• These moles need to come out!
Skin cancer prevention
• Avoid sunburns
• Sunscreen
• Tanning beds
• Hats and sunshirts
• Skin exam and biopsy!
Key points
• Look carefully at the skin
• Ask about sunburns, FH of melanoma and mole changes
• Biopsy or fond someone to biopsy
• Early detection can be lifesaving; esp in melanoma
• Avoid sunburns and counsel on protection
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