Skin soft tissue and plastics Flashcards
What are keratinocytes?
Main cell in the epidermis. Originate from the basal layer. Provides a mechanical barrier.
What is the origin of melanocytes?
Neuroectodermal (neural crest cells) origin. Located in the basal layer. Have dendritic processes that transfer melanin to neighboring keratinocytes and malanosomes. Density of melanocytes is the same among races. Difference is amount of melanin produced.
What is the role of Langerhans cells?
Langerhans cells (dendritic cells) – act as APC MHC class II. Originate from BM. Has a role in contact hypersensitivity type IV
Sensory nerves:
- Pacinian corpuscles – deep pressure
- Ruffini’s endings – warmth, skin stretch
- Krause’s end bulb – cold
- Meissner’s corpuscles – light pressure, tactile sense
What is the function of eccrine and apocrine sweat glands?
Eccrine:
Produce aqueous sweat for thermal regulation, usually hypotonic. Spread all over the body, with high concentration in palms and soles of feet.
Apocrine sweat gland - Milky sweat. Limited to the axilla, groin, anus.
- Hydradenitis is infection of apocrine sweat gland
Most sweat of above two is the result of sympathetic nervous system via ACH
Treatment for hydradenitis
Treatment for mild topical antibiotics or oral IV
Moderate to severe TNF alpha inhibitor adalimumab
dapsone or cyclosporine provide variable results
Unroofing the sinus tracts mild disease
Pyoderma gangrenosum
- RF: antiperspirant, down syndrome, African Americans, obesity, female gender
- Tx: 1st hygiene (Avoid anti-perspirant) (avoid excessive sweating by avoiding hot climate) and abx.
- Surgical treatment provides best chance for cure complete excision with split thickness skin graft
- Don’t excise with any active infection
What is the predominant type of collagen in the skin?
Type I collagen, comprising 70% of the dermis, providing tensile strength.
Tension – resistance to stretch (collagen)
Elasticity - ability to regain shape (branching proteins can stretch 2x normal length)
Cushing’s striae - Decreased collagen results in loss of tensile strength and elasticity in dermis.
Stretch marks – damage to dermal collagen, blood vessel dilation and neovascularization occur
What is the main complication of a pedicled or anastomosed free flap?
Free flap – detached from blood supply, inserted into another portion of body with microvascular anastomosis
Pedicled flap – uses original blood supply
MCC of pedicled or anastomosed free flap necrosis → venous thrombosis
Myocutaneous flap - blood supply to skin is from muscle perforators
Never do a flap with active infection
What is a TRAM flap?
Tissue expansion occurs by local recruitment, thinning of the dermis and epidermis, mitosis
TRAM flap, transverse rectus abdominis musculocutaneous. = PEDICLED FLAP
- Is musculocutaneous flaps – takes skin, subq and underlying muscle
- Blood supply - superior epigastric vessels.
- Periumbilical mm perforators most important determinant of TRAM flap viability.
- Avoid left sided TRAM if previous CABG with left IMA use – compromises superior epigastric vessel
- Can’t use with previous transverse laparotomy that’s high (Chevron incision)
- Use contralateral rectus if chest XRT was used for breast CA (internal mammary artery compromised)
- Lap chole not a contraindication
- Highest risk for complications with smoking and obesity
- Complications – flap necrosis, ventral hernia, abdominal wall weakness
What is a DIEP flap?
Deep inferior epigastric perforator flap, a free tissue transfer that takes fat and skin only.
Deep inferior epigastric perforator (DIEP) = FREE TISSUE TRANSFER
- Most commonly used for breast reconstruction
- Takes fat and skin only, no rectus muscle from lower abdomen = fasciocutaneous flap
- Anastomosis of inferior epigastric vessels to internal mammary artery and vein in the chest
- Major advantage less complications from donor site
- Nerves and muscle not disturbed = less plain
- Shorter hospital stay
- Decreased risk of hernia at donor site
- Lower rate of fat necrosis
- Disadvantage Requires microsurgery operation is much longer
- Can’t use on left if previous CABG with IMA use
- Replaced TRAM due to few complications with abdominal wal
What is the first step in diagnosing a suspicious skin lesion?
Start with incisional biopsy (SCC and BCC) UNLESS concerned about melanoma, then you MUST do full thickness punch biopsy first and make sure to get down to SUBQ FAT
For most Soft tissue tumor start with Core needle biopsy
If that is non-diagnostic, then do incisional biopsy
Basal cell carcinoma
MC cancer in the US
80% head and neck.
Malignancy of upper lip is almost always BCC
Rare on the lower lip
Rare nodal mets
Originates from epidermis – basal epithelial cells and hair follicles
Slow growth
Pearly, Waxy, with telangiectasias. Center ulceration with “rolled borders”
Morpheaform type - most aggressive has collagenase production
Peripheral palisading nuclei and stromal retraction on pathology
Rares mets or nodes
Regional adenectomy for rare clinically positive nodes
MC type is nodular
Tx: 4-5 mm margin. Unless high risk (morpheaform) 1 cm margin
- Do a lymphadenectomy only for clinically positive nodes
- Can do Moh’s surgery as first line treatment as well
If excision of SCC or BCC is not possible: radiation
What is Moh’s surgery?
Moh’s Surgery – Confirms complete excision, takes as little tissue as possible
Indications: > 2 cm or cosmetically sensitive areas or positive margins after excision
What is the recommended margin for excision?
4-6 mm margin down to subcutaneous fat.
When is post-operative radiation needed?
For all with positive nodes, perineural invasion, and positive margins.
What is the procedure for clinically positive nodes?
FNA/excisional biopsy; if positive, perform lymphadenectomy then radiation.
What is the treatment for parotid basin lesions with clinically positive nodes?
Superficial parotidectomy and MRND.
What is the treatment if excision of SCC or BCC is not possible?
Radiation.
What margin is needed for Marjolin’s ulcer or penile/vulvar lesions?
For Marjolin’s ulcer or penile/vulvar = need 1-2 cm margin
Can treat high risk with Mohs surgery (minimizes area of resection) when resecting areas of face or highly sensitive areas
What is the most common soft tissue sarcoma?
Undifferentiated pleomorphic sarcoma.
What is the second most common soft tissue sarcoma?
Liposarcoma.
Where are most soft tissue sarcomas located?
In the extremities (40%). Amputation is almost never the answer. Always limb sparing
What is the prognosis for soft tissue sarcoma?
Very high local recurrence rate.
What is the most common presentation of soft tissue sarcoma?
Sx: present with asymptomatic growing mass = MC presentation. GI bleed, bowel obstruction, neuro deficit
What is the most common site for metastasis in soft tissue sarcoma?
Hematogenous spread!! Mets to nodes are rare
Biopsy: Will show spindle cells, arise from mesenchymal tissue
Lung MC site for mets
What is the most important prognostic factor for soft tissue sarcoma?
Staging is based on tumor grade (undifferentiated is worse)
Most important to improve survival R0 surgical resection
Tumor grade is the most important prognostic factor. Other prognostic factors, tumor size, pathologic stage
What are the risk factors for soft tissue sarcoma?
Asbestos (mesothelioma), PVC, arsenic, vinyl chloride, thorotrast -> angiosarcoma, chronic lymphedema (lymphangiosarcoma), previous radiation.
Soft tissue sarcoma dx/ staging
- Need the below imaging BEFORE any biopsy – need it to rule out vascular, nerve or bone invasion
- All extremity/trunk/head/neck sarcomas need an MRI
- All retroperitoneal lesions need abdominal CT These also need core needle biopsy
- After imaging CORE NEEDLE BIOPSY always first choice, if unable to get or fails then below:
- Longitudinal incisional biopsy
- Need to eventually resect biopsy skin site if + for sarcoma
- Biopsy along the long axis plane of future incision for resection
- Don’t raise flaps, or disturb tissue planes. Do not enucleate. Just do incisional biopsy leaving bulk behind
- !!!For visceral or retroperitoneal sarcoma – Imaging can be diagnostic, if it’s not then will need CNBx
Staging:
- Chest CT to rule out lung mets
Soft tissue sarcoma tx
Tx:
- Radical EN-BLOC resection with grossly negative, 1 cm margins and include the fascia. No frozen section.
- Myxofibrosarcoma and dermatofibrosarcoma protuberans need 2 cm margins
- Need to include incision/core needle biopsy scars in resection
- If nerves, vessels are near resection, they should be keletonized
- >5 cm or high-grade Neoadjuvant radiation, especially if you want to downsize tumor
- >5 cm or high-grade positive margins, recurrence if didn’t give neoadjuvant radiation, need adjuvant here
- Neoadjuvant chemo for high grade tumors > 10 cm
- < 5 cm, > 1 cm margin, low grade Do not need radiation
- If you have positive margin go back to OR for resection, PLUS give radiation!!
- Local recurrence resect only if you can get R0 resection
- Chemo and XRT have not changed survival, only decrease local recurrence
- Chemo has very limited role in sarcoma of extremities
- Always attempt limb salvage, try to avoid amputation
- If sarcoma massively involves nerves, vessels, bone and would require amputation Do neoadjuvant radiation
- Isolated mets should be resected!! Pulmonary metastectomy improves overall survival
- Only need wedge resection
- Midline incision for pelvic or retroperitoneal sarcomas
- Try to preserve motor nerves, and renal vessels
Poor prognosis for retroperitoneal sarcoma overall due to
- Delay in diagnosis
- Difficulty with resection
- Difficulty getting XRT to pelvic and retroperitoneal tumors
- 40% 5-year survival rate with complete resection
Post mastectomy reconstruction
Post mastectomy reconstruction are either flap based or implant based:
- Flap based – Must be delayed until after radiation. Much larger surgery
- Implant based – uses tissue expanders 1st, THEN place implant after radiation. Generally, require 2 surgeries.
Pressure sores:
Pressure sores:
- Stage I - non-blanchable erythema, skin intact. Tx: keep pressure off
- Stage II – Partial, epidermis is lost, and into dermis. Tx: Local treatment, keep pressure off
- Stage III – Full thickness. Through the dermis. SubQ fat exposure tx: sharp debridement. Likely need myocutaneous flap
- Stage IV – Involves fat, bone, muscle or tendon exposed. Tx: Myocutaneous flap
- Unstageable – If you cannot see the depth due to eschar or slough
UV radiation
UV radiation
Damages DNA and repair mechanisms
RF for SCC, basal cell, and melanoma
Melanin single best factor for protecting skin from UV radiation. Absorbs radiation and dissipates as heat
UV-A- Causes skin aging/wrinkling. Also has some part in CA. Responsible for tanning
UV-B causes SKIN DAMAGE, sunburn, and has greatest damage to DNA and role in causing cancer
Melanoma Risk Factors:
- Genetic risk factors are the highest risk!!
- Familial BK mole syndrome – 100% risk of melanoma
- Having > 50 moles on body
- Fair complexion
- Sun exposure, mostly UVB that causes CA, some with UVA found in tanning beds
- Xeroderma pigmentosum
- XRT
- 10% of melanomas familial
Familial atypical multiple mole and melanoma
Many moles on body
- Risk of melanoma and pancreatic cancer
- P16, CKD4
Melanoma
MC in back for men, legs for women
Worse prognosis for high mitotic rate, increased thickness, men, ulcerated, ocular, mucosal, increased # of nodes, location on back, posterior arms/neck/scalp
Blue color most ominous sign
Originates from neural crest cells (melanocytes) in the basal layer of epidermis
MC site for mets is lung
MC mets to small bowel is melanoma
Check tumor for BRAF mutation can target with immunotherapy
Dabrafenib Targets BRAF, indicated for treatment of unresectable or metastatic melanoma that harbors BRAF
Check for PD-1 mutation Targeted with Pembrolizumab
Stains for S-100 and HMB-45 protein
Dx:
- Always start with punch biopsy, and make sure to get down to SUBQ FAT – biopsy the most suspicious (Most pigmented, most irregular, most raised) area
- Face, hands feet - always want punch biopsy
- Can get excisional biopsy with 1 mm margin for lesions < 2 cm – NOT in cosmetically sensitive area
Thin melanoma = < 1 mm depth
Intermediate melanoma = 1-4 mm
Thick melanoma = > 4 mm
Staging: CT ch/abd/pelvis, LFT, LDH for all melanoma > 1 mm. Examine all draining LN
Tx: Resection, go down to muscle/fascia.
- In situ = 0.5 cm margin
- ≤1 mm = 1 cm margin
- ≥1.1- 2.0 mm = 1 - 2 cm margins
- > 2.0 mm = 2 cm margins
Isolated SINGLE mets to lung, liver, EVEN BRAIN should be resected - This is best chance for cure. Provided patients with long term survival
For disseminated metastasis immunotherapy
IL-2 and tumor vaccines used for node or metastasis
Melanoma Types
Types:
- Melanoma in situ or thin lentigo maligna (Hutchinson’s Freckle) - just the epidermis. Can do 0.5 cm margins
- Lentigo maligna melanoma - least aggressive. Radial growth 1st. Presents as elevated nodule.
- Superficial spreading - MC type. Intermediate malignancy, originates from nevus or sun exposed area
- Acral lentiginous - very aggressive. Palm/soles of African Americans. Subungual (fingernail)
- Nodular - Most aggressive. Most of them have metastasized at the time of dx. Vertical growth. Bluish black with smooth borders. Occurs anywhere on the body
Melanoma Nodes:
Nodes:
- Four nodal basins: inguinal, axillary, parotid, and cervical
- Melanoma that require SLNBx:
- All > 0.8 mm depth
- If < 0.8 mm and has any below:
- Ulcerated lesion
- High mitotic rate
- If SLNBx positive you have two option
- US surveillance Q4 months (preferred)
- Completion lymphadenectomy
- Clinically positive nodes do FNA 1st, if inconclusive excisional biopsy. If positive = formal resection
- You are trying to clear the tumor, not stage (like breast CA).
- Parotid basin: scalp/face melanoma anterior to ear and above upper lip, including earALL need superficial parotidectomy AND SLNBx (20% mets to parotid)
- If superficial parotid gland is positive for CA total parotidectomy and MRND
- If SLNBx is positive need MRND vs US
- If clinically positive nodes superficial parotidectomy and MRND
- Axillary node melanoma (or any other nodal basin) and no primary tumor found→ complete axillary dissection I, II, and III (unlike breast CA) primary tumor may have regressed or is unpigmented
- May need to divide pectoralis minor to get to level III nodes
- Superficial inguinal lymph node dissection- first biopsy node of Cloquet, if positive, also need deep nodes.
- Boundaries of dissection in femoral triangle - inguinal ligament superiorly, adductor magnus medially, sartorius
Line of Sappey – 2 cm above umbilicus at L2/L3
- Above line melanoma goes to axillary nodes
- Below line melanoma goes to inguinal nodes
Subungal melanoma
If melanoma in situ wide length excision
Remove nail and get a punch biopsy
Thumb – amputate DIP
Finger – amputate PIP
Great Toe – Amputate at mid proximal phalanx. Never do a ray amputation of great toe if you can avoid it. Need it for balance
Rest of toes – amputate mid proximal phalanx
SCC of skin
Overlying erythema. Papulonodular with crust. Scaly plaques. Ulceration with pink borders. Red-brown. Satellite nodules
Mets more common than BCC
Skin malignancy of lower lip is almost always SCC
MC skin cancer in transplant patients. Considered HIGH risk in them b/c immunosuppressed
Can develop after XRT or old burn scars
Actinic keratosis – precursor to SCC. Described as a sand paper like rash. Tx: topical 5FU 1st line or Imiquimod. Can do surgery cauterize the lesions
Keratoaconthoma = Central keratin filled plug. Risk of Cancer Tx: Excision
RF = HPV, sun exposure, xeroderma pigmentosum, Bowen’s disease, atrophic epidermis, previous XRT
RF for mets: poorly differentiated, greater depth, recurrent lesions, immunosuppression
Tx: 4-6 mm margin down to subcutaneous fat. Can do Moh’s
- Post-op radiation needed for all with positive nodes, perineural invasion, and positive margins
- Clinically positive nodes FNA/excisional biopsy if positive lymphadenectomy then radiation
Parotid basin lesion with clinically positive nodes superficial parotidectomy and MRND
If excision of SCC or BCC is not possible radiation
Head and neck sarcoma
Usually in pediatric, usually get rhabdomyosarcoma
Difficult to get margins due to proximity of vital structures
Post op XRT for close margins (you basically can never get a full resection here)
Retroperitoneal sarcoma
CT abd/pelv = sufficient for diagnosis. Imaging can be diagnostic, however always get core needle biopsy when possible.
MC is liposarcoma. Also, leiomyosarcoma is common
Especially poor prognosis due to delayed diagnosis and incomplete resection. Also, trouble with XRT due to proximity of vital structures
Ability to completely remove the tumor (take kidney, colon, liver if need be) is the most important prognostic factor
Debulking of primary or recurrent tumors is NOT recommended. Fails to improve overall survival. Only operate if you can get all the tumor or if there is an obstruction you need to relieve.
!!!!Adjuvant radiation or chemotherapy is not standard of practice for retroperitoneal liposcarcomas!!!!!
Need to rule out lymphoma MC retroperitoneal tumor overall
Kaposi’s Sarcoma
Vascular sarcoma
Oral and pharyngeal mucosa are the MC sites. Bleeding, dysphagia
Rarely a cause of death for AIDS slow growing
Tx: Primary goal is palliation
- AIDS Tx shrinks AIDS related KS best tx
- Surgery for severe intestinal hemorrhage
Childhood rhabdomyosarcoma
1 soft tissue sarcoma in kids
Head/neck MC site in children
Embryonal subtype – MC
Alveolar subtype – worst prognosis
Rhabdomyosarcoma contains desmin
Botryoides vaginal rhabdomyosarcoma
Tx: Surgery; doxorubicin based chemo
Bone sarcoma
Most are metastatic at the time of diagnosis
Osteosarcoma - increased incidence around knee. Originates from metaphyseal cells. Usually in children
- Mets to lung should be resected if can get all of it, and primary tumor resected
Li-Fraumeni syndrome
– Autosomal Dominant familial cancer with p53 tumor suppressor mutation.
- Diagnosis requires:
- Patient has a diagnosis of soft tissue Sarcoma (childhood rhabdomyosarcoma) CA before 45
- Have a 1st relative diagnosed with any cancer before 45
- Have another 1st or second degree relative diagnosed with sarcoma at any age or any other CA before 45
- Most common two cancers: rhabdomyosarcoma and breast cancer 70% risk
Retinoblastoma
RB, also includes sarcomas, melanoma
VHL
VHL – RCC, hemangioblastoma of retina and CNS, pheochromocytoma
Tuberous sclerosis
Tuberous sclerosis - Angiomyolipoma
Gardner’s syndrome
Gardner’s syndrome – FAP and intra-abdominal desmoid tumors
Dermatofibrosarcoma protuberans
Dermatofibrosarcoma protuberans – soft tissue tumor
Excellent survival rate, rarely metastasizes. However, they recur locally, often
Flesh colored plaques on skin. CD34 positive. Tumor from fibroblasts. Pathology shows finger like projections of spindle cells
- Tx: wide local excision with 2 cm margins
- Imatinib for locally advanced or metastatic tumor
Neurofibromatosis, AD:
- Neurofibromatosis I (von Recklinghausen) –peripheral sheathe tumors (neurofibroma, neurolemma), pheochromocytoma.
- NF type II – Only get acoustic neuromas
- AD
- café-au-lait spots, axillary freckling
Acanthosis nigricans
paraneoplastic dermatosis
Usually affects and intertriginous areas (axilla, groin, knees and elbows)
Velvety thickened hyperkeratotic plaques
Associated with DM and insulin resistance
New onset in older patients, associated with malignancy MC gastric, also lung CA
When found on palms concern for CA
Xanthoma
Xanthoma - cholesterol rich, yellow, contains histiocytes. Benign
Neuroma
Neuroma – associated with NF/von Recklinghausen’s, peripheral and CNS tumor
Keratosis
- Actinic keratosis - Premalignant to SCC of skin. Sun damaged area. Need excisional biopsy if suspicious. Tx: topical 5FU
- Seborrheic keratosis – NOT premalignant. Trunk on elderly. Dark.
- Arsenical keratosis - associated with SCC
Keratoacanthoma
- rolled edges, crater filled with keratin
- Risk of squamous cell CA
- Always bx these
- Tx: excision
Merkel cell carcinoma of skin
Neuroendocrine
Very aggressive, Spreads to nodes
Expands rapidly
Pink then progresses to purple or blue to violaceous nodules or plaques
“blue skin lesions”
MC mets to bone
Merkel cell polyomavirus genome found in tissue samples
Cytokeratine-20 positive. CK20
Have neuron specific enolase NSE, neurofilament protein
Keratin bodies show perinuclear pattern
Initial work up: US of lymph node basins and total body scanning
Tx:
- Wide local excision, sentinel LNBx and post op radiation
need 1-2 cm margin
Glomus tumor
Painful, composed of blood vessels and nerves
Benign.
MC in the terminal aspect of digit
Tx: tumor excision
Paraganglioma
Rarely malignant, neural crest cells
Part of autonomic nervous system
From Glomus cells
MC location: abdomen. MC ENT location: carotid body
Can secrete norepi, highly vascular
Tx: excision
Felon
Abscess in the fingertip, does not involve nail bed
Tx: Must DO incision and drainage in midline of digital pulp. Avoid lateral incisions (injures nerves)
Paronychia
Abscess at edge of fingernail
Tx: Warm compress, unless systemic effects then Incision at the lateral nail fold
Retroperitoneal fibrosis
-Periaortic, surrounds ureters and causes obstruction of ureter, and acute renal failure
- MC idiopathic, other causes is methysergide, XRT
- Elevated ESR
- Medial deviation of ureters is classic on CT
- Malignant tumors can cause retroperitoneal fibrosis, so you if there is suspicion for CA rule out with CT guided biopsy
- Treatment:
o Give all patients steroids 1st line
o Relieve obstruction (stents or nephrostomy tube)
- Mainstay of treatment is steroids for mild hydronephrosis without renal compromise
- If renal function compromised or moderate to severe hydronephrosis 1st line: Place ureteral stents
o 2nd line: Nephrostomy tubes
- Surgery reserved for refractory to medical management with ureterolysis and wrap ureter with omentum
Epidermal inclusion cyst
- Epidermal inclusion cyst (sebaceous cyst, epidermoid cyst) - Most common. Have completely mature epidermis with creamy keratin material
Trichilemmal cyst
- Trichilemmal cyst – In scalp. No epidermis. Contain keratin from hair follicles
Ganglion cyst
- Ganglion cyst – Found over joints. Usually wrist. Filled with synovial fluid. Tx: Treatment is surgical excision of symptomatic. Leave alone otherwise. Aspiration has high recurrence risk. Need to remove the check valve with surgery.
Dermoid cyst
- Dermoid cyst – Midline intra-abdominal and sacral lesions usual. Needs resection due to risk of malignancy
Pilonidal cyst
Use elliptical incision to encompass all the skin and SubQ, Go down to presacral fascia
Make incision off of midline to decrease tension if needed
Most conservative management is unroofing the pilonidal sinus tract
Keloid
Keloid – Genetic!! Autosomal dominant
More common In African American
Contains disorganized Type I and type III collagen
Occurs due to failure of collagen breakdown
Excision has 100% recurrence rate
Tx: 1st silicone pressure dressings, if that fails then intralesional steroids
Hypertrophic scarring
Not genetic
Contains well-organized type III collagen
Occurs due to hypervascularization
Tx: 1st silicone pressure dressings, if that fails then intralesional steroids
Order of healing of skin grafts
Melana lower extremity, palpable lymphadenopathy
-Dissection of superficial inguinal lymph node basin
-6 to 10 cm incision extending from 2-4 cm below inguinal ligament
-Saphenous vein at junction of sartorius and adductor muscles: preserved
-Lateral cutaneous femoral nerve running under fascia of sartorius (preserved)
-Femoral nerve, artery, vein within femoral triangle: preserved
-Cloquet’s node within femoral canal: excise and close defect in lacunar ligament
-Mesh or sartorius flap can be used to cover residual defects