Tumour iSAWE 5

Question

A 55 year old man has a painless 8 cm mass in his posterior thigh that has grown over 6 months. It is deep to the fascia.

Tumour iSAWE 5, axial mri
Axial MRI. Image by Jmarchn, Wikimedia Commons, CC BY-SA 3.0.
  1. What features suggest malignancy?
  2. How would you investigate this mass?
  3. Outline the principles of management.

Answer

Features suggesting malignancy

  • Size over 5 cm
  • Deep to the deep fascia
  • Increasing size
  • Pain
  • Recurrence after previous excision

Investigations

  • MRI of the thigh before any biopsy
  • Referral to a sarcoma service
  • Core needle biopsy at the sarcoma centre, along the line of the planned excision
  • CT of the chest for staging
  • Common subtypes are undifferentiated pleomorphic sarcoma, liposarcoma, myxofibrosarcoma and synovial sarcoma

Management principles

  • Avoid unplanned excision (the whoops procedure), which contaminates tissue and compromises limb salvage
  • Wide excision with a cuff of normal tissue
  • Radiotherapy, given before or after surgery, for high grade, deep or large tumours, with preoperative radiotherapy causing more wound complications but less fibrosis
  • Chemotherapy for selected subtypes such as synovial sarcoma and rhabdomyosarcoma
  • Follow up for local recurrence and lung metastases

Related pages

Author Contributions

Orthofracs team

Reviewed by Professor Phong Tran, Head of Orthopaedic Surgery, Western Health. Last updated 10 October 2026.