Common skin lesions Flashcards
Epidermal cyst presentation
Round, yellow/flesh-coloured, slow growing, mobile, firm, fluctuant, nodule or tumour
Epidermal cyst pathophysiology
Epithelial cells displaced into dermis, epidermal lining becomes filled with keratin and lipid-rich debris
May be post-traumatic, rarely syndromic
Epidermal cyst epidermiology
most common cutaneous cyst in youth - middle age
Epidermal cyst clinical course
central punctum may rupture (foul, cheesy odour, creamy colour) and produce inflammatory reaction Can increase in size and number over time)
Epidermal cyst management
no treatment elective excision
Pilar cyst (Trichillemmal) clinical presentation
Multiple, hard, variable sized nodules under the scalp, lacks central punctum
Pilar cyst (Trichillemmal) pathophysiology
Thick-walled cyst lined with stratified squamous epithelium and filled with dense keratin Idiopathic Posttraum
Pilar cyst (Trichillemmal) epidemiology
2nd most common cutaneous cyst F>M
Pilar cyst (Trichillemmal) clinical course
rupture causes pain and inflammation
Pilar cyst (Trichillemmal) management
no tx, elective excision
dermoid cyst clinical presentation
Firm nodule most commonly found at lateral third of eyebrow or midline under nose
dermoid cyst pathophys
Rare congenital hamartomas, which arise from inclusion of epidermis along embryonal cleft closure lines, creating a thick-walled cyst filled with dense keratin
dermoid cyst epi
rare
dermoid cyst clinical course
If nasal midline, risk of extension into CNS
dermoid cyst management
no tx, elective excision
ganglion cyst clinical presentation
Usually solitary, rubbery, translucent; a clear gelatinous viscous fluid may be extruded
ganglion cyst pathophys
Cystic lesion that originates from joint or tendon sheath, called a digital mucous cyst when found on fingertip
Associated with osteoarthritis
ganglion cyst epi
older age
ganglion cyst clinical course
stable
ganglion cyst management
no treatment
incision and experession of contents
elective excision
milium clinical presentation
1-2 mm superficial, white to yellow subepidermal papules occurring on eyelids, cheeks and forehead
milium pathophys
Small epidermoid cyst, primarily arsing from pluripotential cells in epidermal or adnexal epithelium Can be secondary to blistering, ulceration, trauma, topical corticosteroid atrophy, or cosmetic procedures
milium epi
any age
40-50$ of infants
milium clinical course
in newborns spontaneously resolves in first 4 weeks of life
milium tx
no tx
incision and expression of contents
electrodessication
topical retinoid therapy
Fitzpatrick scale
I - always burns, never tans
II - always burns, little tan
III - slight burn, slow tan
IV (pale brown) - slight burn, faster tan
V - (brown) - rarely burns, dark tan
VI (dark brown or black) - never burns, dark tan
Dermatofibroma clinical presentation
button-like, firm dermal papule or nodule, skin-coloured to red-brown
- majority are asymptomatic but may be pruritic and/or tender
- site: legs > arms > trunk
- dimple sign (Fitzpatrick’s sign): lateral compression causes dimpling of the lesion
Dermatofibroma pathophy
benign tumour due to fibroblast proliferation in the dermis
Dermatofibroma etiology
- unknown; may be associated with history of minor trauma (e.g. shaving or insect bites)
- eruptive dermatofibroma can be associated with SLE
Dermatofibroma epi
adults F>M
Dermatofibroma ddx
• dermatofibrosarcoma protuberans
malignant melanoma
Kaposi’s sarcoma
blue nevus
Dermatofibroma investigations
biopsy if diagnosis uncertain
Dermatofibroma management
no tx required, excision if bothersome
skin tags clinical presentation
- small (1-10 mm), soft, skin-coloured or darker pedunculated papule, often polypoid
- sites: eyelids, neck, axillae, inframammary, and groin
skin tags pathophys
benign outgrowth of skin
skin tags epi
• middle-aged and elderly, F>M, obese, can increase in size and number during pregnancy
skin tags ddx
• pedunculated seborrheic keratosis
compound or dermal melanocytic nevus
neurofibroma
fibroepithelioma of Pinkus (rare variant of BCC)
skin tags management
excision
electrodessication
cryosurgery
skin tags are also known as
acrochordones
fibroepithelial polyps
seb keratosis clinical presentation
known as ‘wisdom spots,’ ‘age spots,’ or ‘barnacles of life’
- well-demarcated waxy papule/plaque with classic “stuck on” appearance
- rarely pruritic
- over time lesions appear more warty, greasy and pigmented
- sites: face, trunk, upper extremities (may occur at any site except palms or soles)
seb keratosis pathophys
• very common benign epithelial tumour due to proliferation of keratinocytes and melanocytes
seb keratosis epi
- unusual <30 yr old
- M>F
- autosomal dominant inheritance
- Leser-Trelat sudden appearance of SK that can be associated with malignancy, commonly gastric adenocarcinomas
seb keratosis ddx
• malignant melanoma (lentigo maligna, nodular melanoma)
melanocytic nevi
pigmented BCC
solar lentigo
spreading pigmented AK
seb keratosis investigations
biopsy if unsure
seb keratosis management
none req, cosmetic only
cryotherapy, electrodessication, excision
Corns (helomata) clinical presentation
- firm papule with a central, translucent, cone-shaped, hard keratin core
- painful with direct pressure
- sites: most commonly on dorsolateral fifth toe and dorsal aspects of other toes
Corns (helomata) pathophys
• localized hyperkeratosis induced by pressure on hands and feet
Corns (helomata) epi
• F>M, can be caused by chronic microtrauma
Corns (helomata) ddx
callus
plantar wart
Corns (helomata) management
- relieve pressure with padding or alternate footwear, orthotics
- paring, topical salicylic acid
corns vs warts vs calluses
- Corns have a whitish yellow central translucent keratinous core; painful with direct pressure; interruption of dermatoglyphics
- Warts bleed with paring and have a black speckled central appearance due to thrombosed capillaries; plantar warts destroy dermatoglyphics (epidermal ridges)
- Calluses have layers of yellowish keratin revealed with paring; there are no thrombosed capillaries or interruption of epidermal ridges
keloids clinical presentation
- firm, shiny, skin-coloured or red-bluish papules/nodules that most often arise from cutaneous injury (e.g. piercing, surgical scar, acne), but may appear spontaneously
- extends beyond the margins of the original injury, and may continue to expand in size for years with claw-like extensions
- can be pruritic and painful
- sites: earlobes, shoulders, sternum, scapular area, angle of mandible
keloids pathophy
• excessive deposition of randomly organized collagen fibres following trauma to skin
keloids epi
- most common in black patients, followed by those of Asian descent (predilection for darker skin)
- M=F, all age groups
keloids managemetn
- intralesional corticosteroid injections
* silicone compression
keloids vs hypertrophic scars
keloids extend beyond margins of original injury with claw-like extensions
hypertrophic scars are confined to original margins of injury
congenital nevomelanocytic nevi (CNMN) clinical presentation
sharply demarcated pigmented papule or plaque with regular borders ± coarse hairs
• classified by size: small (<1.5 cm),
medium M1: 1.5-10 cm, M2: >10-20 cm),
large (L1: >20-30 cm, L2 >30-40 cm),
giant (G1: >40-60 cm, G2: >60 cm)
• may be surrounded by smaller satellite nevi
congenital nevomelanocytic nevi (CNMN) pathophy
• nevomelanocytes in epidermis (clusters) and dermis (strands)
congenital nevomelanocytic nevi (CNMN) epi
- present at birth or develops in early infancy to childhood
- malignant transformation is rare (1-5%) and more correlated with size of the lesion
- neurocutaneous melanosis can occur in giant CNMN (melanocytes in the central nervous system)
congenital nevomelanocytic nevi (CNMN) management
- take a baseline photo and observe lesion for change in shape, colour, or size out of proportion of growth
- surgical excision if suspicious, due to increased risk of melanoma
- MRI if suspicious for neurological involvement
ddx of hyperpigmented macules
- Purpura (e.g. solar, ASA, anti-coagulants, steroids, hemosiderin stain)
- Post-inflammatory
- Melasma
- Melanoma
- Fixed drug eruption
cafe-au-lait macule clinical presentation
Flat light brown lesions with smooth or jagged borders
cafe-au-lait macule patohophys
Areas of increased melanogenesis
cafe-au-lait macule epi
6 or more is suggestive of neurofibromatosis type I
Also associated with McCune Albright syndrome
cafe-au-lait macule ddx
Flat congenital melanocytic nevus, speckled lentiginous nevus
cafe-au-lait macule clinical course and management
enlarge in proportion to the child
No effective treatment
speckled lentiginous nevus (nevus spilus) clinical presentation
Brown pigmented macular background (caféau-lait macule-like) with dark macular or papular speckles
speckled lentiginous nevus (nevus spilus) pathophys
Increased melanocyte concentration
speckled lentiginous nevus (nevus spilus) epi
Risk of melanoma similar to that of a CNMN of the same size
speckled lentiginous nevus (nevus spilus) ddx
Café-au-lait macule, agminated lentigines, Becker’s nevus
speckled lentiginous nevus (nevus spilus) clinical course and management
usually the light macular background is present at birth and speckles develop over time. Management is similar to that of CNMNs
Dermal melanocytosis (historically known as Mongolian Spot) clinical presentation
Congenital greyblue solitary or grouped macules commonly on lumbosacral area
Dermal melanocytosis (historically known as Mongolian Spot) pathophys
Ectopic melanocytes in dermis
Dermal melanocytosis (historically known as Mongolian Spot) epi
99% occurs in Asian and Indigenous infants
Dermal melanocytosis (historically known as Mongolian Spot) ddx
Ecchymosis
Dermal melanocytosis (historically known as Mongolian Spot) clinical course and management
usually fades, may persist
halo nevus
often a typical appearing nevus surrounded by a ring of depigmentation; not rare in children; uncommonly associated with vitiligo; no treatment required unless irregular colour or borders
blue nevus
round to oval macule/papule with homogenous blue to blue-black colour; often appears in childhood and late adolescence; no treatment required unless atypical features are noted
acquired nevomelanocytic nevi clinical presentation
- common mole: well circumscribed, round, uniformly pigmented macules/papules <1.5 cm
- average number of moles per person: 18-40
- 3 stages of evolution: junctional NMN, compound NMN, and dermal NMN
acquired nevomelanocytic nevi management
- new or changing pigmented lesions should be evaluated for aypical features which could indicate a melanoma
- excisiona biopsy should be considered if the lesion demonstrates asymmetry, varied colours, irregular borders, pruritus or persistent bleeding
junctional acquired nevomelanocytic nevi onset, clinical presentation and histology
childhoood, majority progress to compound
Flat, regularly bordered, uniformly tan-dark brown, sharply demarcated macul
Melanocytes at dermal-epidermal junction above basement membrane
compound acquired nevomelanocytic nevi onset, clinical presentation and histology
Any age
Domed, regularly bordered, smooth, round, tan-dark brown papule Face, trunk, extremities, scalp NOT found on palms or soles
Melanocytes at dermal-epidermal junction; migration into dermis
dermal acquired nevomelanocytic nevi onset, clinical presentation and histology
Adults
Soft, dome-shaped, skin-coloured to tan/brown papules or nodules Sites: face, neck
Melanocytes exclusively in dermis
Atypical nevus (dysplastic nevus) clinical presentation
Variegated macule/ papule with irregular distinct melanocytes in the basal layer Risk factors: family history
Atypical nevus (dysplastic nevus) pathophys
Hyperplasia and proliferation of melanocytes extending beyond dermal compartment of the nevus Often with region of adjacent nests