Soft Tissue Sarcoma

Soft tissue sarcomas are a heterogeneous group of malignant mesenchymal tumours arising from:

Muscle
Fat
Fibrous tissue
Blood vessels
Peripheral nerves
Other connective tissues

There are many histological subtypes and they do not all respond to the same systemic therapy.

Important examples include:

Undifferentiated pleomorphic sarcoma
Liposarcoma
Leiomyosarcoma
Synovial sarcoma
Myxofibrosarcoma
Malignant peripheral nerve sheath tumour
Angiosarcoma
Epithelioid sarcoma

The strongest broad prognostic factors are:

Histological grade
Tumour size
Depth
Metastatic disease
Surgical margin

Most extremity sarcomas spread haematogenously, particularly to the lungs. Routine lymphadenectomy is unnecessary because nodal spread is uncommon except in selected histologies.

Typical presentation is a painless enlarging soft tissue mass.

A soft tissue mass requires urgent sarcoma assessment when it is:

Increasing in size
Deep to fascia
Approximately 5 cm or larger
Painful without another explanation
Recurrent after previous excision

Small superficial sarcomas do occur, so size alone cannot exclude malignancy.

Do not assume that a painless mass is benign.

A common serious error is unplanned excision of a presumed lipoma before imaging or biopsy.

MRI with contrast: investigation of choice for extremity and trunk lesions.

Define:

Size
Fascial compartment
Neurovascular relationship
Bone involvement
Internal necrosis

CT chest: standard metastatic staging for most intermediate and high grade extremity sarcomas because lung metastases predominate.

Biopsy

Image first, then biopsy.

Use image guided core needle biopsy in most cases.

The tract should:

Follow a direct longitudinal path
Avoid uninvolved compartments
Avoid neurovascular bundles
Avoid creating a transverse scar
Be placed so it can be removed with the tumour specimen

Do not shell out or excise an undiagnosed deep mass before pathology is established.

Patients treated at specialist sarcoma centres have better local control than patients managed through unplanned procedures.

Localised extremity sarcoma

The cornerstone is wide surgical resection with negative margins.

The objective is removal of tumour with an intact surrounding cuff of uninvolved tissue or an anatomical barrier.

A microscopically negative margin does not require sacrificing a major nerve or vessel merely to achieve an arbitrary centimetre distance when an intact fascial barrier provides an oncologically appropriate margin.

Remove the biopsy tract with the specimen.

Limb salvage

Most extremity soft tissue sarcomas can now be treated with limb preserving surgery.

Amputation is reserved for selected cases where:

Adequate margins cannot otherwise be achieved
Major neurovascular involvement prevents a functional reconstruction
Severe infection or tissue destruction eliminates meaningful salvage

Radiotherapy

Radiotherapy substantially improves local control for many intermediate and high grade sarcomas but has not clearly improved overall survival across all disease.

Use particularly for:

Deep tumours
Large tumours
High grade disease
Close anatomical margins
Sites where local recurrence would be difficult to salvage

Preoperative radiotherapy commonly uses approximately:

50 Gy in 25 fractions

Advantages:

Smaller treatment field
Lower long term fibrosis burden

Disadvantage:

Higher acute wound complication risk

Postoperative radiotherapy commonly requires approximately:

60 to 66 Gy

depending on margins and local anatomy.

Advantages:

Final pathology is known before radiation

Disadvantages:

Larger treatment field
Greater late fibrosis and stiffness

Small low grade tumours

A small superficial or selected low grade tumour that is completely excised with a satisfactory margin may not require radiotherapy.

Systemic chemotherapy

Routine chemotherapy is not required for every resected adult soft tissue sarcoma.

Consider perioperative chemotherapy in selected high risk disease according to:

Histology
Size
Grade
Site
Patient fitness

Advanced disease

A standard reference first line treatment for many metastatic adult soft tissue sarcomas is:

Doxorubicin 75 mg/m² IV every 3 weeks

for a limited cumulative course according to cardiac tolerance.

Doxorubicin remains the reference systemic agent for many advanced subtypes.

Doxorubicin plus ifosfamide provides a higher response rate and longer progression free survival but substantially greater toxicity, without a consistent overall survival advantage. It is most useful when rapid tumour shrinkage is particularly important.

Treatment after progression is histology specific and may include:

Pazopanib
Trabectedin
Eribulin
Gemcitabine based treatment
Ifosfamide
Dacarbazine

depending on subtype.

Pulmonary metastases

Pulmonary metastasectomy can provide long term disease control in carefully selected patients with:

Controlled primary tumour
Limited pulmonary disease
Long disease free interval
Ability to remove all metastatic deposits

Nodal disease

Routine sentinel node or lymph node dissection is unnecessary for most sarcomas.

Greater nodal propensity occurs in selected histologies including:

Epithelioid sarcoma
Clear cell sarcoma
Angiosarcoma
Some synovial sarcomas

Clinically involved nodes should be investigated and managed according to histology.

Unplanned excision

A patient referred after inadvertent excision of a sarcoma should undergo:

MRI of the operative field
Chest staging
Pathology review
Wide reexcision of the contaminated tumour bed when feasible

Residual microscopic disease is common even when the original wound appears normal.

Clinical toolsCalculators

BMI GCS EDD Parkland Formula

Corrected Sodium Corrected Calcium Anion Gap Creatinine Clearance Insulin Calculations qSOFA Wells PE Wells DVT CHA₂DS₂-VASc HAS-BLED CURB-65 Centor/McIsaac

Chondrosarcoma

Chondrosarcoma is a malignant tumour in which neoplastic cells produce cartilage matrix.

It predominantly affects adults.

Common sites include:

Pelvis
Proximal femur
Proximal humerus
Ribs
Scapula

The major biological distinction is between lower grade conventional cartilage tumours and aggressive high grade or specialised chondrosarcoma subtypes.

Histological grade

Grade 1

Low grade tumour with relatively low metastatic potential.

In appendicular sites, some lesions previously termed grade 1 chondrosarcoma are classified as atypical cartilaginous tumour because their metastatic risk is very low.

Grade 2

Intermediate grade, with greater local aggressiveness and metastatic potential.

Grade 3

High grade tumour with substantial metastatic risk.

Important specialised subtypes include:

Dedifferentiated chondrosarcoma
Mesenchymal chondrosarcoma
Clear cell chondrosarcoma

These behave differently from conventional low grade disease.

Plain radiographs: often show a destructive lesion with chondroid matrix mineralisation.
MRI: define medullary extent, soft tissue extension and relation to major neurovascular structures.
CT: particularly useful for matrix calcification and cortical destruction.
CT chest: stage intermediate and high grade disease for pulmonary metastases.
Biopsy should occur only after imaging and multidisciplinary planning.

Sampling error is important because large cartilage tumours can contain areas of differing histological grade. Target the most aggressive appearing component.

Surgery

Surgery is the principal curative treatment for most chondrosarcomas. Conventional chondrosarcoma responds poorly to standard chemotherapy and radiotherapy.

Atypical cartilaginous tumour of an extremity

A small asymptomatic lesion without aggressive radiological features can sometimes be observed.

A symptomatic or progressive lesion can undergo:

Extended intralesional curettage

with:

High speed burr
Local adjunct according to practice
Bone graft or cement reconstruction

This preserves the adjacent joint and generally provides good control for appropriately selected appendicular low grade lesions.

Higher grade conventional chondrosarcoma

Grade 2 and 3 tumours require wide en bloc resection with negative margins.

Do not perform curettage of a high grade lesion.

The operation may require:

Endoprosthetic reconstruction
Pelvic resection
Chest wall reconstruction
Biological reconstruction

Margins have major prognostic importance.

Pelvic and axial chondrosarcoma

Even apparently low grade pelvic cartilage tumours behave more aggressively and are much harder to salvage after recurrence.

Pelvic and axial chondrosarcomas generally require wide surgical excision rather than intralesional treatment.

Dedifferentiated chondrosarcoma

This consists of conventional cartilage tumour adjacent to a high grade noncartilaginous sarcoma.

It has:

High metastatic risk
Poor prognosis
High local recurrence risk

Treatment requires wide resection.

Systemic chemotherapy can be considered, often using osteosarcoma type agents in younger and fit patients, but treatment responsiveness is substantially less predictable than conventional osteosarcoma.

Mesenchymal chondrosarcoma

This rare subtype is more chemotherapy sensitive than conventional chondrosarcoma.

Treatment commonly combines:

Wide resection
Multiagent systemic chemotherapy
Radiotherapy in selected cases

Systemic treatment frequently resembles Ewing sarcoma treatment.

Clear cell chondrosarcoma

Usually lower grade but locally recurrent if inadequately excised.

Treat with wide resection.

Radiotherapy

Conventional chondrosarcoma is relatively radioresistant.

Radiotherapy has a role for:

Unresectable disease
Inadequate margins when reoperation is impossible
Skull base and spinal disease where complete resection is unsafe
Palliation

High precision proton or carbon ion techniques can be valuable in selected axial tumours.

Metastatic disease

Pulmonary metastasectomy can be considered when:

Disease is limited
Primary tumour is controlled
Complete pulmonary resection is achievable

Systemic treatment depends heavily on subtype and molecular findings rather than using one generic chondrosarcoma regimen.

Soft Tissue Sarcoma

Overview

Clinical Features

Diagnosis

Management

Overview

Clinical Features

Diagnosis

Management