Transcript How To Approach a “bump” - McMaster University's

Michelle Ghert, MD, FRCSC
HOW TO APPROACH A “BUMP”
EPIDEMIOLOGY:
300/100,000 benign soft-tissue, but
only 2/100,000 malignant soft-tissue
 Soft tissue sarcoma can occur at any age
Rabdomyosarcoma most common in children
 Synovial & epitheliod sarcomas common in
young adults
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20-40% of STS occur in extremities
 1/3 in upper extremities & 2/3 lower
extremities
 30% occur in trunk and pelvis.
 10% occur in head & neck
 1/3 of STS present as small superficial
masses
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STS & THEIR TISSUE OF ORIGIN:
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Fibrous Tissue
Adipose Tissue
Striated Tissue
Smooth Tissue
Synovial Tissue
Blood Vessels
Lymph Vessels
Peripheral Nerve
Myofibroblast
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Fibroma/Fibrosarcoma
Lipoma/Liposarcoma
Rhabdomyoma/Sarco
Leiomyoma/Sarcoma
Mesothelioma
Angioma/Sarcoma
Lymphangioma/sarco
Neuroma/Schwannoma
Malignant Fibrous
Histiocytoma
BRAIN STORMING:
Superficial tender mass, red in color,
rapidly enlarging, swollen, warm,
fluctuant on examination?
1)Synovial cyst
2)Hematoma
3)Abscess
Hx of direct trauma, therapeutic anticoagulation,
clotting deficiency, subcutaneous ecchymosis,
compressible on examination?
1)Abscess
2)Hematoma
3)Synovial Cyst
Para-articular mass, trans-illuminate, fluctuation in size
independent of activities, tense but indentable with
digit pressure on examination?
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Bakers cyst
Hematoma
Shwannoma
Synovial Cyst
COMMON SOFT TISSUE LESIONS:
Malignant:
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Pleiomorphic Sarcoma
Fibrosarcoma(FS)
Liposarcoma
Synovial Sarcoma
Epitheliod Sarcoma
Clear Cell Sarcoma
Rhabdomyosarcoma
Benign:
1-Lipoma
2-Desmoid
3-Schwannoma
4-Hemangioma
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MEMORIAL SLOAN-KETTERING CLINICAL
STAGING:
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Size:
< 5cm
>= 5cm
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Depth:
Superficial
Deep
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Grade:
Low
High
GUIDELINE TO HISTOLOGIC GRADING
OF SARCOMAS:
LOW GRADE:
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Good Differentiation
Hypocellular
More Stroma
Hypovascular
Minimal Necrosis
HIGH GRADE:
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Poor Differentiation
Hypercellular
Minimal Stroma
Hypervascular
Much Necrosis
LABORATORY EVALUATION:
Very little information is gained.
 Some infections may result in elevated:
WBC, ESR & CRP
But this finding nonspecific.
 Elevated lactate dehydrogenase seen in
lymphoma.
 Suspicion of Gout----- Serum Uric Acid
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ULTRASOUND:
Confirm the diagnosis of a cyst
 Does mass have a cystic component?
 F/U a small mass that is being followed without
excision
 Accurately asses an increase in growth of the
mass by examining the change on the
ultrasound studies
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CT:
Identifying and characterizing mineralization
within the soft tissue masses(myositis
ossification)
 Generally reserved for staging
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MRI:
Most sensitive and specific radiograph study
for imaging soft tissue masses
 Helpful for preoperative planning prior to
excision the mass
 Excellent differentiation of various tissue types
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BIOPSY OF SOFT TISSUE MASSES:
Indication:
1- Clinical & radiographic evaluation does not
yield a conclusive diagnosis
2-When the mass must be removed
2 CRITERIA SHOULD BE MET BEFORE
PROCEEDING:
1) The pathologist should have experience in
musculoskeletal pathology
2)The surgeon should have experience in dealing
with all of the possible diagnoses considered
in the pre-biopsy differential diagnosis
TYPES OF SOFT TISSUE BIOPSY:
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Fine-needle aspiration
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Core-needle
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Open biopsy
CORE AND FNA:
Typically performed by an interventional or
MSK radiologist
 Minimal morbidity for the patient
 Core is better than FNA
 Core is 85% diagnostic
 If non-diagnostic tissue is obtained, the
mass should not be assumed to be
benign
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OPEN BIOPSY:
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Incision in line with resection incision
Longitudinal in extremities
Intramuscular if possible (to bury hematoma)
Avoid NV structures and joints
No skin or muscle flaps
Meticulous hemostasis
Tight closure
Approach soft tissue mass or weakened area of
bone
Drain if necessary, in line and distal to incision
Send tissue for frozen: ‘lesional tissue’
THE SURGEON’S APPROACH TO A BUMP:
Treatment of soft tissue masses is based on
their size and location
 4 categories:
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 small
superficial
 large superficial
 small deep
 large deep
INTRALESIONAL EXCISION:
The piecemeal removal of the tumor.
 Benign proliferative lesions (PVNS, gout)
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MARGINAL EXCISION (SHELL-OUT)
Complete removal of the tumor with
pseudocapsule left intact
 Benign tumors
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WIDE EXCISION:
Removal of the tumor with a cuff of normal
tissue without exposing the pseudocapsule
 Malignant soft-tissue lesions
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RADICAL EXCISION:
Involves removal of the entire muscle
compartment or compartments involved by the
tumor
 Rare
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SMALL SUPERFICIAL TUMOR:
Less than 5cm
 Easily palpable beneath the skin & not firm
with muscle contracture
 Slow or stable growth pattern
 Long history
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If excisional biopsy is chosen, then marginal
excision can be done
 Deep fascia should be left undisrupted
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LARGE SUPERFICIAL TUMOR:
More than 5 cm.
 Easily felt beneath the skin, and not firm with
muscle contracture.
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Almost always need
evaluation with MRI
 If a diagnosis is
unclear by MRI, then
biopsy
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SMALL DEEP TUMOR:
Less than 5 cm located in deep fascia
 Becomes more firm with muscle contracture
 Small deep mass should be always investigated
by MRI
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If MRI suggests a lipoma or peripheral nerve
sheath mass (shwannoma), marginal excision
 Non-specific MRI may represent a soft tissue
sarcoma
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LARGE DEEP TUMOR:
More than 5cm located deep to the fascia.
 MRI (high risk)
 Refer to musculoskeletal oncologist
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SARCOMA MANAGEMENT
Wide surgical excision
 Radiation, pre or post operative
 Chemotherapy, while controversial, can be
considered for patient with high grade, large,
deep soft tissue sarcoma
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TAKE HOME POINTS FOR ‘BUMPS’
Longstanding, small, static subcutaneous
‘bumps’ can be treated with ultrasound,
observation and marginal excision if desired
 Rapid growth, deeper lesions and those 4-5 cm
should be imaged with MRI
 High-risk lesions should not be excised, but
biopsied
 Always use longitudinal incision in extremities
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WHEN IN DOUBT, GIVE US A CALL!