Plastics Flashcards
Three types of dermal appendage
Hair follicles
Sweat glands
Sebaceous glands
Escape destruction in partial-thickness burns and have a source of new cells for reconstitution of the epidermis
Type of sweat gland affected by hidradenitis suppurativa
Apocrine
Hidradenitis suppurativa affects apocrine sweat glands - secrete must liquid into axilla, ears, eyes, nipples, perianal region, genitals
Types of sweat gland
Eccrine: secrete salt and water for skin
Apocrine: musty liquid
-Hidradenitis suppurativa
Stages of wound healing
Lag phase
- 2-3 days
- inflammatory response
Proliferative phase
- 3 weeks
- Fibroblast migration
- Capillary ingorwth (granulation)
- Collagen synthesis and gain in tensile stremgth -Wound contraction
Plateu phase
- 6 months
- Organisation of scar
- Slow final gain in tensile strength (80% of original)
Use of flaps
Flaps are used when the recieving site has a poor blood supply and hence a graft won’t take
e.g. over joints, tendons, bone
Eschar
Epidermis and dermis are converted into a coagulum of dead tissue
Fluid loss due to oedema
An increase of 2 cm in the diameter of the leg represents the accumulation of over 2 litres of excess
interstitial fluid.
IV fluids in burns
Required in burns >15% adults
> 10% Children
Parkland formula
4 X weight (kg) X %BSA
1/2 over 8 hours,
1/2 over the next 16 hours
Sebaceous cysts
Sebaceous or epidermoid cysts
Dermal swellings covered by epidermis
Thin wall of flattended epidermal cells and contain sebum + epitheial debris
Soft smooth hemispherical swellings over which the skin cannot be moved.
Surface punctum
Infection: cyst becomes hot, red and painful.
Infected cysts are incised to allow the infected material to escape.
Excision is deferred until the inflammation has settled.
Dermoid cysts
Arise from nests of epidermal cells that have been sequestered in the dermis during development or implanted from trauma
Lined by squamous epithelium and
contain sebum, degenerate cells and, in some cases, hair.
A soft rubbery swelling forms deep to the skin.
Congenital dermoid cysts found at sites of embryonic fusion: face, base of nose, forehead, occipit
- External angular dermoid most common: lies at junction of maxilla frontal bones on later superior orbit
Congenital dermoid cysts
Found at sites of embryonic fusion: face, base of nose, forehead, occipit
External angular dermoid most common: lies at junction of maxilla frontal bones on later superior orbit
Senile warts (seborrhoeic kerratosis)
Basal cell papillomas
Common in the elderly
Form yellow-ish brown or black greasy plaque
Cracked surface that falls off in pieces
Tx: Curettage
Keratocanthoma
Hemispherical nodule with friabl red centre encrusted with keratin
Often of the face, >50 years of age
Grows rapidly over 6-8 weeks
Heals by shedding its keratin core
Clinically looks like squamous cell carcinoma
–> histologically it can resemble SCC but has a well defined “shoulder”
Actinic keratosis
Actinic (solar) keratosis
Pre-malignant keratosis
Small singular/multiple firm warty spots on the face, back, neck hands
Scaly lesions drop off to reveal underlying pre-malignant ulcer
Mx: biopsy to exclude malignancy and then cryotherapy if non-malignant
Bowen’s disease
Intra-epidermal skin cancer
Non-invasive, discrete solitary raised brown fissured plaque containing kerratin
Hyperplastic atypical epithelial cells, but there is no
evidence of invasion through the basement membrane
If affects penis or vulvula: erythroplasia of de Queyrat
Basal cell carcinoma
Rodent ulcer
Slow growing, locally invasive cancer
Never metastasize
Commonly arise on middle third of face: nose or inner canthus of eye
Hard pearly nodule dimpled in its centre and covered by thin telangiectatic skin
Types:
- Cystic
- Nodular
- Sclerosing
- Morphoeic
- Centrally healing
- Field fire
Squamous cell carcinoma
Can affect any area but common on sun-exposed areas
Develops in an area of epithelial hyperplasia or keratosis.
In mucosa: leucoplakia
Hard erythematous nodule, which proliferates to form a
cauliflower-like excrescence or ulcerates to form a malignant ulcer with a raised fixed hard edge.
Grows more quickly than a rodent ulcer but more slowly than a keratoacanthoma
Palpable lymph nodes require regional lymphadenectomy by block dissection
Adjuvant radiotherapy may be required if histology
shows extracapsular spread
Lentigo maligna
Hutchinson’s melanocytic freckle
Commonly on face in elderly women
Originate as red-brownish patch the grows slowly, advancing and receeding over years
The edge of the lesion appears serrated
Kaleidoscopic pigmentation of the surface i
Malignancy: brownishred papule that develops eccentrically within the freckle
Superifcial spreading melanoma
Most common melanoma
Trunk and exposed parts, middle age
Pre-invasive phase: 1 or 2 years, malignant cells spread
outwards (horizontal growth phase) in the epidermis
Pigmentation is patchy and there may be a wide range
of colours
Invasion of the dermis (vertical growth phase) occurs while the lesion is still relatively small and produces
an indurated nodule, which soon ulcerates or bleeds.
Nodular melanoma
Elevated, deeply pigmented melanoma
Any site
Any age
Vertical invasion from the start, no horizontal spreading stage (hence no surrounding pigmented macule)
Nodule enlarges steadily, both centrifugally
and on the surface
Lesion darkens progressively, jet black and glossy
Bleeding
Crusting
Itching, irritation and ulceration
Satellite nodules may form around neglected lesions.
Breslow depth
1cm of clearance for every 1mm depth
up to 3cm
Tumour and surrounding skin are excised down to the deep fascia
Staging of malignant melanoma
Three stages
I Primary lesion only
Breslow depth
II Primary lesion + regional lymph node or satellite deposit
III Metastatic disease
