Skin and Soft Tissue—Sarcoma
Concept
Pathologic type is not as important as size, grade, location, and resection margins. Lymph node involvement is rare and therefore, lymph node dissections are only done if grossly involved. Chemotherapy is controversial and mar- ginally beneficial.
Way Question May be Asked?
“39 y/o man presents to the office with a growing mass on his right anterior thigh. On exam, it is hard and fixed to the underlying tissues. What do you do?” May be in the extremity of a female after axillary dissection (Stewart- Treeves syndrome) or in patient with history of radiation.
How to Answer?
Brief History
Trauma Radiation
Café au lait spots (von Recklinghausen pts) History of prior lymphadenectomy
Physical Exam
Examination of tumor Lymph nodes
Neurovascular deficit in the affected extremity
Studies
CXR
MRI/CT for extremity sarcomas (MRI more helpful in retroperitoneum to allow evaluation of the IVC)
Biopsy Lesion
If less than 3 cm, may excise, but don’t shell out due to tumor pseudo encapsulation→ aim for 2 cm margin If larger, incisional biopsy parallel to the muscle group
(won’t compromise future resection)
Core needle biopsy is acceptable but tattoo site of bx for later excision
Need to ask pathologist: histologic grade
Treatment
Surgical excision for grossly clear margin In extremity:
2 cm margin, remove entire muscle group only if nec- essary
Mark the excision site for adjuvant XRT that may reduce incidence of local recurrence
Can leave microscopic disease if this preserves vital neurovascular structures as post-op XRT will clean up residual disease
Extremity arteries are expendable and can be replaced with vein or conduit
Femoral nerve can be sacrificed, but not sciatic (gen- erally, can sacrifice sensory nerves, but try to pre- serve motor nerves)
Removing large central extremity veins leaves pt with severe edema
Amputative procedures only for joint involvement (hip, knee, elbow, shoulder, pelvis)
For small-cell sarcomas (Ewing’s), can consider neoadjuvant chemo/XRT to cytoreduce tumors to allow for limb salvage or salvage of vital neurovascular structures (sciatic nerve)
In retroperitoneum:
Wide local resection for grossly clear margins only Resect en bloc only organs where sarcoma is clearly
invaded
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Dissect sarcoma free if adherent to an intra-abdom- inal structure
No indication for use of adjuvant RT in retroperi- toneal sarcomas (too much visceral toxicity) Only do percutaneous biopsy if there is extensive
peri-aortic adenopathy and the dx is most likely lymphoma
Can excise IVC if involved and replace with Gortex if pt hasn’t already developed sufficient collateral around it.
Pulmonary Mets
Acceptable to remove if primary disease site is con- trolled and number of pulmonary mets < 8
Common Curveballs
Retroperitoneal sarcoma will abut or invade multiple intraabdominal organs
Extremity sarcoma will invade neurovascular bundle Recurrence locally (re-excise in extremity if possible or
amputate)
Development of lung metastases
IVC will be invaded in retroperitoneal sarcoma Upper extremity sarcoma
Strikeouts
Attempt an FNA of mass
Incisional biopsy transverse to underlying muscle group Trying to treat only with chemotherapy (only small cell
sarcomas!)
Removing adjacent organs in retroperitoneal sarcoma if no actual invasion
Removing entire muscle group when clear margin can be achieved with less aggressive surgery
Not attempting pulmonary metastectomy when sar- coma recurs in lungs
Resecting sciatic nerve
Not preparing pt pre-op for possible paralyzed leg or amputation in attempt to perform adequate resec- tion
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