18 Plastics, Skin, Soft tissue flaps Flashcards
Keratinocytes
Main cell type in epidermis
Originate from basal layer
Provides mechanical barrier
Melanocytes
Neuroectodermal origin (neural crest cells)
In basal layer of epidermis
Transfer melanin to neighboring keratinocytes via melanosomes through dendritic processes
Density of melanocytes is the SAME amongst races - different rate of melanin production
Dermis
Structural proteins (collagen)
Langerhans cells
Antigen-presenting cells - MHC Class II
Originate from bone marrow
Contact hypersensitivity reactions (Type IV)
Pacinian corpuscles
Pressure
Ruffini’s endings
Warmth
Krause’s end-bulbs
Cold
Meissner’s corpuscles
Tactile sense
Eccrine sweat glands
Aqueous sweat - hypotonic
Thermal regulation
Apocrine sweat glands
Milky sweat
Most in palms and soles
Acetylcholine (BUT still sympathetic nervous system)
What type of drugs have best skin absorption?
Lipid-soluble drugs
Predominant type of collagen in skin?
Type I collagen
70% of dermis
Gives tensile strength
Definition - tension
Resistance to stretching
Collagen
Definition - elasticity
Ability to regain shape
Branched proteins that can stretch 2x normal length
Cushing’s striae
Caused by loss of tensile strength and elasticity
MCC of pedicled or anastomosed free flap necrosis?
venous thrombosis
How does tissue expansion occur?
Local recruitment
Thinning of the dermis and epidermis
MItosis
TRAM flaps
Transverse rectus abdominis myocutaneous
Complications: flap necrosis, ventral hernia, bleeding, infection, abdominal wall weakness
Blood supply - superior epigastric vessels
Most important determinant of TRAM flap viability?
Periumbilical perforators
Stage I pressure sore
Erythema and pain
No skin loss
Stage II pressure sore
Partial skin loss with yellow debris
Tx: Local, keep pressure off
Stage III pressure sore
Full-thickness skin loss, subcutaneous fat exposure
Tx: Sharp debridement; likely need myocutaneous flap
Stage IV pressure sore
Involves bony cortex, muscle
Tx: myocutaneous flap
UV radiation
Damages DNA and repair mechanisms
Both a promoter and initiator
Melanin is the single best factor for protecting skin from UV radiation
What radiation is responsible for chronic sun damage?
UV-B
Risk factors for melanoma?
Dysplastic, atypical, large congenital nevi (10%) Familial BK mole syndrome (100%) Xeroderma pigmentosum Fair complexion, easy sunburn, intermittent sunburns Previous skin CA Previous XRT Immunosuppression 10% familial
Most common melanoma site on skin?
Men - back
Women - legs
Negative prognostic factors for melanoma?
Men
Ulcerated lesions
Ocular and mucosal lesions
Signs of melanoma?
Asymmetry (angulations, indentation, notching, ulcerations, bleeding) Borders irregular Color change Diameter increasing Evolving over time
Most omnious sign for melanoma?
Blue clor
Most common site for distant melanoma metastases?
Lung
Most common metastasis to small bowel?
Melanoma
Diagnosis of melanoma?
<2cm lesion - excisional biopsy
>2cm lesion (or cosmetically sensitive) - incisional biopsy (punch biopsy)
Thin lentigo maligna
Melanoma in situ, Hutchinson’s freckle
Just in superficial papillary dermis
0.5cm margins OK
Lentigo maligna melanoma
Least aggressive
Minimal invasion
Radial growth first
Elevated nodules
Superficial spreading melanoma
Most common
Intermediate malignancy
Originates from nevus/sun-exposed areas
Acral lentiginous
Very aggressive
Palms/soles of AA
Nodular melanoma
Most aggressive
Generally has metastasized at time of diagnosis
Vertical growth first
Bluish-black with smooth borders
Staging workup for melanoma?
For all melanoma >1mm deep:
- Chest/abd/pelvic CT
- LFTS
- LDH
- Examine all possible draining lymph nodes
Treatment for all stages of melanoma?
1) Resection of primary tumor with appropriate margins
2) Management of lymph nodes
Surgical margins for melanoma?
In situ (0.5-1.0cc)
<1.0mm (1.0cm)
1.1-2.0mm (1-2.0cm)
>2.0mm (2.0cm)
Involved nodes in melanoma - signs?
Non-tender
Round
Hard
1-2cm
When do you reset nodes in melanoma?
Clinical positive nodes
When do you do a SLNB in melanoma?
Clinically negative nodes
Tumor >1mm deep
Tumors >0.72mm deep with worrisome factors
What do you need to add with anterior head/neck mealnomas >1mm?
Superficial parotidectomy (20% met rate to parotid)
Approach to axillary node melanoma with no other primary?
Complete axillary node dissection
Remove levels I, II and II - unlike breast CA
Medical treatment for systemic melanoma disease?
IL-2
Tumor vaccines
Most common malignancy in united states?
Basal cell carcinoma of the skin
Origin of basal cell carcinoma?
EPidermis - basal epithelial cells and hair follicles
Pearly appearance, rolled borders, slow and indolent growth
Basal cell carcinoma
Path - peripheral palisading of nuclei, stromal retraction
Basal cell carcinoma
Basal cell carcinoma - morpheaform type
More aggressive
Has collagenase production
Treatment of basal cell carcinoma?
Margins - 0.3-0.5cm
XRT/chemo - inoperable disease, metastasis, neuro/lymph/vessel invasion
Overlying erythema, papulonodular with crust/ulcers; red-brown
Squamous cell carcinoma
Marjolin ulcer
Squamous cell carcinoma in post-XRT areas or old burn scars
Risk factors for squamous cell carcinoma
Actinic keratosis Xeroderma pigmentosum Bowen's disease Atrophic epidermis Arsenics Hydrocarbons (coal tar) Chlorophenols HPV Immunosuppresion Sun exposure Fair skin previous XRT Previous skin CA
Risk factors for metastasis of squamous cell carcinoma
Poorly differentiated
Greater depth
Recurrent lesions
Immunosuppression
Treatment of squamous cell carcinoma?
Margins 0.5-1cm
Mohs surgery (high risk)
Regional adenectomy for clinically positive nodes
XRT/Chemo - inoperable disease, mets, neuro/lymph/vessel invasion
Most common soft tissue sarcomas?
1# Malignant fibrous histiosarcoma
2# Liposarcoma
Symptoms of soft tissue sarcoma?
Symptomatic mass
GI bleed
Bowel obstruction
Neurologica deficits
Work up of soft issue sarcoma?
CXR - r/o lung mets MRI - r/o vascular, neuro, bone invasion Biopsy: - < 4cm - excisional - >4cm - longitudinal incisional
Mets of soft tissue sarcomas?
Hematogenous spread
Rarely to LN
Most common site - lung
Most common site of soft tissue sarcoma mets?
Lung
Treatment of soft tissue sarcoma?
3cm margins and at least 1 uninvolved fascial plane
Place clips - if recurrence, XRT
Indications for postop XRT for soft tissue sarcoma?
High-grade tumors
Close margins
Tumors >5cm
Chemotherapy for soft tissue sarcoma?
Doxorubicin
Indication for preop chemo-XRT with soft tissue sarcoma?
> 10cm
Possibility of limb-sparing resection
Poor prognostic factors in soft tissue sarcoma?
Delay in diagnosis
Difficulty getting total resection
Difficulty getting XRT to pelvic tumors
Head and neck sarcomas?
Pediatric - usually rhabdomyosarcoma
Post-op XRT for positive or close margins
Visceral and retroperitoneal sarcomas?
Most common leiomyosarcoma and liposarcoma
Risk factor for mesothelioma
Asbestos
Risk factor for angiosarcoma
PVC and arsenic
Risk factor for chronic lymhedema
Lymphangiosarcoma
Kaposi’s sarcoma
Vascular sarcoma
Oral/pharyngeal mucosa most common - bleeding, dysphagia
Immunocompromised - AIDS
Tx: Palliation, HAART< XRT, Vinblastin, INF-a
Childhood rhabdomyosrcoma
#1 soft tissue sarcoma in kids Head/neck, GU, extremities, trunk Embryonal subtype - most common Alveolar subtype - worst prognosis Tx: Surgery, doxorubicin
Osteosarcoma
Increased incidence around the knees
Originates - metaphyseal cells
CHildren
Neurofibromatosis
CNS tumors, peripheral sheath tumors, pheochromocytoma
Li-fraumeni syndrome
Childhood rhabdomyosarcoma and others
Hereditary retinoblastoma
Includes other sarcomas
Tuberous sclerosis
Angiomyolipoma
Gardner’s syndrome
Familial adenomatous polyposis adn itnra-abdominal desmoid tumors
Xanthoma
Yellow, contains histiocytes
Tx: Excision
Warts
Verruca vulgaris
Viral, contagious, autoinoculable, painful
Tx: Liquid nitrogen
Actinic keratosis
Premalignant sun-damaged areas
Tx: excisional biopsy if suspicious
Seborrheic keratosis
NOT premalignant
Trunk on elderly
Can be dark
Arsenical keratosis
Associated with squamous cell CA
Merkel cell carcinoma
Neuroendocrine
Very aggressive - early regional and systemic spread
Red to purple papulonodule or indurated plaque
Neuron-specific enolase (NSE), cyutokeratin, neurofilament protein
Glomus cell tumor
Painful tumor composed of blood vessels or nerves
Benign
Most common in terminal aspect of the digit
Tx: Tumor excision
Desmoid tumors
Benign, but locally invasive
Occur in fascial planes
High risk of recurrence, no distance spread
Tx: Surgery, chemo (sulindac, tamoxifen)
Most common location of desmoid tumors
Anterior abdominal wall
Intraabdominal desmoid tumors
Gardner’s syndrome and retroperitoneal fibrosis
Encases bwoel
Bowen’s disease
SCCA in-situ
10% progress to invasive SCCA
Associated with HPV
Tx: Imiquimod, cautery ablation, topical 5-FU
Keratoacanthoma
Rapid growth, rolled edges, crater filled with keratin
NOT malignant, but difficult to differentiate from SCCA
Involutes spontanously over months
Tx:
- Small; excise
- Large; biopsy and observe
Hyperhidrosis
Increased sweating - palms
Tx: thoracic sympathectomy if refractory to antiperspirants
Hidradenitis
Infection of apocrine sweat glands - axilla and groin
Staph/strep
Tx:
- ABx, improved hygiene
- Surgeyr to remove skin and sweat glands
Epidermal inclusion cyst
Most common
Mature epidermis with creamy keratin material
Trichilemmal cyst
In scalp
No epidermis
Ganglion cyst
Over tendons, commonly wrist
Filled with collagen material
Dermoid cyst
Midline intra-abdominal and sacral lesions
Need resection due to malignancy risk
Pilonidal cyst
Congenital coccygeal sinus with ingrown hair
If infected - needs excision
