How to order an ultrasound for a left leg lump?

How to Order an Ultrasound for a Left Leg Lump

For a patient with a left leg lump, the most appropriate initial imaging study is an urgent direct access ultrasound to be performed within 2 weeks to assess for possible soft tissue sarcoma. 1

Initial Assessment and Imaging Selection

Ultrasound as First-Line Imaging

• Ultrasound is the recommended first-line imaging modality for evaluating soft tissue masses, providing effective initial triage and accurate differentiation between benign and malignant masses 2
• The British Sarcoma Group guidelines specifically recommend urgent direct access ultrasound (within 2 weeks) for adults with an unexplained lump that is increasing in size 1

Ordering Process

1. Request form details should include:

   • Patient demographics
   • Clinical history including:
     • Duration of the lump
     • Rate of growth
     • Associated symptoms (pain, tenderness)
     • Location (superficial or deep)
     • Size of the lump
     • Any relevant risk factors (prior radiation, lymphedema, etc.)
   • Specific request for "Left leg soft tissue mass ultrasound"
   • Clinical question to be answered (e.g., "Rule out soft tissue sarcoma")

2. Specify on the order:

   • The exact location of the lump on the left leg (e.g., anterior thigh, calf, etc.)
   • Any concerning features that warrant urgent assessment:
     • Size >5 cm
     • Deep location
     • Rapid growth
     • Associated pain

Follow-Up Based on Ultrasound Results

If Ultrasound Suggests Benign Findings

• Most soft tissue lumps will be diagnosed as benign lipomas and patients can be safely reassured 1
• For benign lipomas:
  • Regular clinical monitoring every 6-12 months is recommended
  • No immediate intervention is necessary unless symptomatic 2

If Ultrasound Findings Are Concerning or Indeterminate

• Consider a suspected cancer pathway referral (appointment within 2 weeks) if:
  • Ultrasound findings are suggestive of soft tissue sarcoma
  • Ultrasound findings are uncertain and clinical concern persists 1
• Proceed to MRI for:
  • Indeterminate or concerning ultrasound findings
  • Deep-seated masses
  • Masses with atypical features 2

Important Considerations

Pitfalls to Avoid

• Inadequate imaging of deep masses can lead to misdiagnosis 2
• Superficial ultrasound may not fully characterize deep-seated masses
• Relying solely on physical examination can lead to incorrect identification of lipomas (only 85% correctly identified by physical examination alone) 2

When to Consider Alternative Imaging

• MRI is indicated for better tissue characterization when ultrasound results are inconclusive 2
• CT scan may be considered if there's concern for bone involvement or calcifications 2

Patient Education

• Inform patients about the importance of follow-up
• Educate on when to return sooner (growth, increased pain, changes in appearance) 2

By following this structured approach to ordering an ultrasound for a left leg lump, you can ensure appropriate and timely evaluation while avoiding unnecessary testing or delays in diagnosis.