What should I do about a new lump on my back that appeared after a massage?

Evaluation and Management of a New Lump on the Back After Massage

You should obtain an urgent ultrasound scan within 2 weeks to evaluate this new lump, as any unexplained soft tissue mass that appears or increases in size warrants immediate imaging assessment to rule out serious pathology. 1, 2

Immediate Assessment

While massage-related lumps can occasionally represent benign post-traumatic changes, the appearance of a new mass requires systematic evaluation:

• Document the exact location relative to anatomical landmarks (over posterior iliac crest, thoracolumbar region, or other spinal levels) 1, 3
• Measure the size using fingertips weekly - masses >5 cm are particularly concerning for malignancy 1, 2
• Assess for red flag symptoms: severe radiating pain, numbness, weakness in lower extremities, or bowel/bladder dysfunction, which could indicate serious complications like spinal hematoma or nerve compression 4, 5, 6
• Determine depth: superficial lumps in the subcutaneous tissue versus deep-seated masses have different diagnostic implications 1, 2

Diagnostic Pathway

Step 1: Urgent Ultrasound (Within 2 Weeks)

Ultrasound serves as the primary triage tool with 94.1% sensitivity and 99.7% specificity for distinguishing benign from malignant soft tissue masses. 1, 2 This should be performed urgently for any unexplained lump that is new or increasing in size. 1

If ultrasound shows benign features (well-circumscribed, hyperechoic/isoechoic to fat, minimal vascularity):

• Most can be safely observed with clinical follow-up every 6-12 months for 1-2 years 1, 2
• Common benign findings include lipomas or post-traumatic changes like episacral lipomas 3

If ultrasound shows suspicious features (heterogeneous appearance, disorganized vascularity, infiltrative margins, size >5 cm with internal blood flow):

• Proceed immediately to MRI for definitive characterization 1, 2
• Refer via suspected cancer pathway for specialist evaluation within 2 weeks 1

If ultrasound findings are uncertain:

• MRI of the affected region must be performed, as ultrasound accuracy drops significantly for deep-seated lesions 1, 2

Step 2: MRI When Indicated

MRI provides the most accurate information for diagnosis and surgical planning for soft tissue tumors. 2, 7 This is particularly important for:

• Deep-seated masses where ultrasound is less reliable 2
• Any mass in the lower limb or deep tissues where atypical lipomatous tumors (well-differentiated liposarcomas) are more common 1
• Cases where clinical concern persists despite benign ultrasound findings 1

Specific Massage-Related Complications to Consider

While rare, massage can cause serious complications that present as new lumps or masses:

Hemorrhagic spinal angiolipomas: Can cause sudden aggravated radicular pain after massage, appearing as epidural lesions with intratumoral hemorrhage on MRI 4

Spinal subdural hematoma: Vigorous massage can cause acute spinal subdural hematoma presenting with severe back pain, motor/sensory deficits, and urinary dysfunction 5

Worsening of pre-existing disc herniation: Massage with spinal manipulation can acutely worsen lumbar disc herniation, potentially causing cauda equina syndrome 6

Episacral lipoma: Small, tender subcutaneous nodules over the posterior iliac crest that can develop after tears in the thoracodorsal fascia, treatable with local anesthetic and steroid injection 3

Critical Pitfalls to Avoid

• Do not assume the lump is simply a benign post-massage hematoma or bruise - any new mass requires imaging evaluation 1, 2
• Do not rely solely on physical examination - clinical recognition of sarcomas is problematic, with median size at diagnosis exceeding 9 cm due to delayed recognition 1
• Do not delay imaging for deep-seated masses - ultrasound accuracy is considerably less for deep lipomas, and these require MRI 2
• Do not ignore neurological symptoms - severe pain, numbness, weakness, or bowel/bladder changes require emergency evaluation for spinal cord or nerve root compression 4, 5, 6

Follow-Up Protocol

If initial imaging shows benign features:

• Physical examination with or without repeat ultrasound every 6-12 months for 1-2 years 1
• If the mass increases in size during follow-up, repeat tissue sampling or biopsy is required 1
• Return to routine screening if the mass remains stable after the observation period 1