Common Presentations
Most patients present with an enlarging mass that may be painful. Locally advanced disease with bone invasion can cause pathological fractures. Unrecognised disease may present with symptoms related to distant metastases.
History
General History
The length of time the lump has been present and the presence of pain should be documented.
Identifying potential causative factors is important:
- Previous radiation exposure
- Chemotherapy as a child
- Exposure to occupational chemicals
- Lymphoedema
- Family History can be particularly important for sarcoma. Some of the well known cancer syndromes such as Li Fraumeni and Retinoblastoma can predispose a patient to development of sarcoma. Neurofibromatosis Type I confers a 10% probability of malignant nerve sheath tumour in a patient's life.
Past History
It is important to identify patient factors that may influence treatment such as severe cardiac or respiratory disease. This can limit surgical options.
Medications / Allergies
Nil specific
Social History
Aside from occupational exposures, nothing specific.
Family History
See above
Examination
Examination of the mass is vital.
- Tethering of the mass should be noted, and whether this is to superficial (skin/subcutaneous structures) or deep (fascia/muscle) structures.
- Neurovascular examination of the limb to detect involvement of peripheral arteries, veins or nerves (important for decision regarding amputation or local excision)
- Regional node examination. Although uncommon in sarcoma lymphatic metastases can occur (particularly for rhabdomyosarcoma, synovial sarcoma or angiosarcoma).
- Respiratory examination to detect pulmonary metastases
- Other examiantion as indicated by history
Investigations
Investigation involves acquiring a histological diagnosis of malignancy (biopsy), followed by determination of local extent and tumour staging with imaging procedures.
Biopsy should be performed by a sarcoma surgeon if possible. This is because tumour recurrence in the biopsy tract has been reported in the literature. Most surgeons will resect the biopsy tract if the patient proceeds to excision. Clinicans with inexperience in dealing with sarcoma may perform a biopsy that then requires more extensive excision. A core biopsy is preferred to assess tumour architecture.
Imaging of the mass is best performed with MRI. This provides excellent contrast between normal soft tissue, oedema and tumour mass.
PET has become an important modality in the staging of soft tissue sarcoma. It provides information on both local tumour extent and the presence of metastatic deposits. A pre-operative PET can also be compared with post-treatment imaging to assess the response to treatment. If PET is not available a CT Chest/Abdomen/Pelvis can be used.
Staging
Staging of peripheral sarcoma is via TNM. Compared to some other sites the staging of soft tissue sarcoma is relatively simple; however, the histological grade of the tumour also plays a role (see the pathology topic).
T Stage
| T Stage | Description |
|---|---|
| T1a | Tumour < 5 cm, superficial |
| T1b | Tumour < 5m, deep |
| T2a | Tumour > 5 cm, superficial |
| T2b | Tumour > 5 cm, deep |
N Stage
| N Stage | Description |
|---|---|
| N1 | Regional nodal metastases |
M Stage
| M Stage | Description |
|---|---|
| M1 | Distant metastases |
Grade
TNM classifies sarcomas as low grade or high grade; where low grade corresponds to Grade 1 for 3-tier systems and Grades 1-2 for 4-tier systems. High grade corresponds to Grade 2-3 in 3 tier systems and 3-4 in 4 tier systems.
Final Stage
| Stage | T | N | M | Grade |
|---|---|---|---|---|
| IA | T1 | N0 | M0 | Low |
| IB | T2 | N0 | M0 | Low |
| IIA | T1 | N0 | M0 | High |
| IIB | T2a | N0 | M0 | High |
| III | T2b Tany |
N0 N1 |
M0 | High Any |
| IV | Tany | Nany | M1 | Any |
