What is the preferred initial imaging modality for a patient with thoracic back pain and a lipoma-like mass at the spine?

Preferred Imaging for Thoracic Back Pain with Lipoma-Like Mass at Spine

MRI of the thoracic spine without and with IV contrast is the preferred initial imaging modality for a patient presenting with thoracic back pain and a lipoma-like mass at the spine. 1

Rationale for MRI with Contrast

The presence of a lipoma-like mass at the spine constitutes a red flag for potential neoplasm, which fundamentally changes the imaging approach from routine thoracic back pain:

• The American College of Radiology explicitly states that MRI without and with IV contrast is the initial imaging modality of choice in patients with thoracic back pain and suspected neoplasm. 1

• The addition of contrast is critical because postcontrast sequences are more sensitive in assessing small marrow-replacing lesions and identifying intradural disease compared to non-contrast MRI alone. 1

• MRI provides superior soft tissue resolution to characterize the mass, assess for cord compression, canal compromise, cord signal abnormality, and evaluate the integrity of neural structures. 1

Why Not Plain Radiography or CT First

• Plain radiographs have low sensitivity for soft tissue masses and are only useful in urgent settings to identify osseous destruction or alignment changes—they cannot adequately characterize a lipoma-like mass. 1

• CT without contrast better depicts osseous detail but is inferior to MRI for soft tissue evaluation and would miss critical marrow pathology and neural structure involvement. 1

• CT is complementary, not primary, and should be reserved for presurgical planning to assess bony anatomy after MRI characterization. 2

Clinical Context: Spinal Lipomas Require Urgent Evaluation

• Spinal lipomas (including angiolipomas, epidural lipomas, and intramedullary lipomas) are rare benign tumors that can cause progressive or acute neurological deterioration through cord compression. 3, 4

• These lesions most commonly occur in the thoracic spine and may present with back pain initially, but can rapidly progress to myelopathy or paraparesis requiring immediate surgical intervention. 3, 4

• Angiolipomas presenting with acute neurological deficits should be immediately treated, making prompt and accurate imaging essential. 3

Critical Pitfalls to Avoid

• Do not order MRI without contrast alone when a mass lesion is suspected—the non-contrast sequences miss critical diagnostic information about enhancement patterns that distinguish benign from malignant lesions. 1

• Do not delay imaging if myelopathy signs emerge, as this requires immediate MRI evaluation. 2

• Be aware that lipomas can mimic other lesions on imaging (such as subacute hematomas), and diffusion-weighted sequences may be needed for definitive characterization. 5

• Do not assume the mass is benign based on clinical appearance alone—ossifying parosteal lipomas and other variants can manifest symptoms due to their location and relationship to skeletal tissues. 6

Algorithm for This Clinical Scenario

1. Order MRI thoracic spine without and with IV contrast immediately as the initial study. 1

2. Assess for red flags during clinical evaluation: myelopathy signs (gait disturbance, hyperreflexia, Babinski sign), radiculopathy, constitutional symptoms, or rapidly progressive symptoms. 1, 2

3. If MRI confirms a compressive lipomatous lesion with neurological compromise, urgent neurosurgical consultation is warranted for potential surgical excision. 3, 4

4. Consider complementary CT without contrast for presurgical planning if surgery is indicated, to better delineate osseous anatomy. 1