What is the best course of action for a patient presenting with multiple lipomas?

Management of Multiple Lipomas

For patients presenting with multiple lipomas, observation is appropriate for asymptomatic lesions <5 cm with typical imaging features, while surgical excision is indicated for symptomatic lipomas, rapidly growing lesions, or those with concerning features requiring specialist evaluation. 1, 2

Initial Clinical Assessment

Key features to document:

• Size, location, growth rate, and presence of pain 2
• Depth (superficial vs. deep-seated) and mobility 3, 2
• Number and distribution of lesions 4

Red flags requiring urgent specialist referral:

• Any lipoma >5 cm in diameter 1, 2
• Deep-seated location (intramuscular, retroperitoneal, or intra-abdominal) 1, 2
• Rapid growth or pain 2
• Lower limb or deep extremity location (higher risk for atypical lipomatous tumor) 1

Diagnostic Imaging Algorithm

For superficial lesions:

• Ultrasound is the initial test of choice with 94.1% sensitivity and 99.7% specificity 3, 2
• Classic ultrasound features include hyperechoic appearance, well-circumscribed borders, minimal internal vascularity, and no acoustic shadowing 3, 2
• Plain radiographs have limited value, identifying intrinsic fat in only 11% of cases 3, 2

When to escalate to MRI:

• Atypical ultrasound features (nodularity, thick septations, stranding) 1, 2
• Deep-seated masses or lesions >5 cm 2
• Diagnostic uncertainty between benign lipoma and atypical lipomatous tumor (ALT)/well-differentiated liposarcoma 1, 2
• MRI can differentiate benign lipomas from ALT in up to 69% of cases 1, 2

Tissue diagnosis:

• Percutaneous core needle biopsy for MDM-2 amplification testing is mandatory when suspicion of ALT exists, as this definitively distinguishes lipoma from ALT and fundamentally alters surgical planning 1, 2

Management Strategy

Observation is appropriate for:

• Asymptomatic lipomas <5 cm with typical imaging features 1, 2
• Superficial location with no concerning features 2
• Patients with significant comorbidities where surgery poses excessive risk 1

Surgical excision is indicated for:

• Symptomatic lipomas (pain, functional impairment, cosmetic concerns) 1, 2, 4
• Rapidly growing lesions 2, 4
• Atypical imaging features 1, 2
• Complete en bloc excision with negative margins (R0) is the standard surgical approach with low recurrence rates 1, 2

Special Considerations for Multiple Lipomas

Surgical planning:

• For patients with numerous lipomas, prioritize excision of symptomatic or concerning lesions first 4, 5
• Large lipomas (10-22 cm) can be safely excised under tumescent local anesthesia in an outpatient setting with lidocaine doses up to 55 mg/kg 2, 6
• Mean skin incision of 4.8 cm can be sufficient for large lipomas when using proper technique 6

Alternative non-surgical option:

• Intralesional deoxycholic acid injections are a safe and effective alternative for patients with multiple lipomas where surgical management is not practical, particularly in adiposis dolorosa (Dercum disease), with demonstrated reduction in pain and improved mobility 5

Mandatory Specialist Referral Criteria

Refer to sarcoma center or surgical oncologist for:

• Any deep-seated mass or mass >5 cm diameter 2
• Retroperitoneal or intra-abdominal location 2
• Atypical MRI features (nodularity, thick septations) 1, 2
• Diagnostic uncertainty between lipoma and ALT 1, 2
• Deep extremity or lower limb masses (higher ALT suspicion) 1

Critical pitfall to avoid: Deep or large lipomatous masses have high local recurrence rates if inadequately excised, and progressive dedifferentiation can occur with each recurrence, making initial appropriate surgical planning essential 2

Post-Excision Follow-Up

• Following complete surgical excision, patients can be discharged to primary care with low recurrence risk 1
• Re-referral is only necessary if clinical suspicion of recurrence develops 1
• At least 1 cm border margin should be taken during excision to avoid local recurrence 7