What is the differential diagnosis for thoracic back pain located on the medial border of the scapula?

Differential Diagnosis for Thoracic Back Pain at the Medial Border of the Scapula

The differential diagnosis for thoracic back pain at the medial border of the scapula must systematically distinguish between benign musculoskeletal conditions and serious underlying pathologies that require urgent intervention, with the thoracic spine being a common site for inflammatory, neoplastic, metabolic, infectious, and degenerative conditions. 1

Musculoskeletal Causes (Most Common)

Spinal Origin

• Thoracic disc herniation: Occurs most commonly below T7, often calcified (20%-65%), and presents with thoracic midback pain (76% of cases), typically in patients aged 30-50 years, with one-third having trauma history 1
• Facet joint arthropathy: Characterized by paravertebral pain aggravated by prolonged standing, hyperextension, or rotation of the thoracic spine 2
• Thoracic radiculopathy: Results from mechanical nerve root compression due to degenerative, metabolic, infectious, or neoplastic causes, presenting as radiating pain in the distribution of an intercostal nerve 1, 2
• Spinal stenosis: Caused by disc herniations, facet arthropathy, or ligamentum flavum ossification, typically below T7 1

Extraspinal Musculoskeletal

• Costotransverse joint arthropathy: An overlooked pain generator presenting as severe pressure sensation and dull pain between the medial scapular borders, often bilateral at T7-10 3
• Myofascial pain: Common benign cause in the thoracic paraspinous soft tissues 1
• Intercostal nerve hypersensitization: Can cause persistent thoracic pain in chronic pain states 4

Serious Pathologies Requiring Red Flag Assessment

Fracture

• Osteoporotic compression fractures: The thoracic spine is a common site, particularly in patients >65 years, those on chronic steroids, or with known osteoporosis 1
• Traumatic fractures: Consider in patients with significant trauma history 1

Malignancy

• Primary or metastatic tumors: Thoracic spine is a common site for neoplastic conditions 1
• Red flags include: Unintentional weight loss, history of malignancy, night pain, constant pain, advanced age 5

Infection

• Spinal infection/osteomyelitis: Consider with fever, recent infection history, immunosuppression 1, 5
• Discitis/epidural abscess: Presents with constant pain and systemic symptoms 1

Inflammatory Conditions

• Ankylosing spondylitis: Consider in younger patients with inflammatory back pain patterns 1
• Psoriatic spondylitis, reactive arthritis, inflammatory bowel disease-related spine disorders: Part of the spondyloarthropathy spectrum 1

Referred Pain from Systemic Conditions

Visceral Sources

• Intrathoracic pathology: Cardiac ischemia (exertional pain, retrosternal radiation, diaphoresis, tachycardia), pulmonary embolism (dyspnoea, hemoptysis), aortic dissection 1, 5
• Gastrointestinal: Peptic ulcer disease (postprandial pain, typical reflux symptoms), pancreatitis 1, 5
• Renal pathology: Nephrolithiasis, pyelonephritis 1

Critical Red Flags Requiring Immediate Evaluation

The combination of multiple red flags significantly increases diagnostic accuracy for serious pathology, whereas single red flags have low diagnostic value. 5

High-Priority Red Flags

• Neurological deficits: Myelopathy signs (motor/sensory deficit 61%, spasticity/hyperreflexia 58%, positive Babinski 55%, bladder dysfunction 24%), saddle anesthesia, loss of anal sphincter tone 1, 5
• Constitutional symptoms: Fever, unintentional weight loss, night sweats 5
• History factors: Advanced age, malignancy history, significant trauma, chronic corticosteroid use, immunosuppression 1, 5
• Pain characteristics: Constant unremitting pain, night pain, progressive worsening 5

Clinical Approach Algorithm

Initial Assessment

1. Determine acuteness: Acute (<4 weeks), subacute (4-12 weeks), or chronic (>12 weeks) 1
2. Screen for red flags systematically: Use multiple red flags in combination rather than relying on single findings 5
3. Assess for neurological compromise: Myelopathy or radiculopathy symptoms require different management 1

Imaging Considerations

• No red flags, acute presentation: Imaging typically not indicated; trial of conservative management for up to 6 weeks 1, 6
• Midline tenderness with fracture risk factors: Thoracic spine radiography as initial study 6
• Myelopathy or radiculopathy: MRI thoracic spine without contrast is the initial imaging of choice 1, 6
• Suspected malignancy or infection: MRI with and without contrast preferred 6

Common Pitfalls

• Over-reliance on single red flags: Leads to high false-positive rates and unnecessary imaging 5
• Assuming all thoracic disc abnormalities are symptomatic: Disc herniations and bulges are common in asymptomatic patients 6
• Missing costotransverse joint pathology: This is an overlooked pain generator that may require specific imaging (CT) to identify 3
• Ignoring visceral referred pain: Always consider cardiac, pulmonary, and gastrointestinal sources, especially with atypical presentations 1, 5

Special Population Considerations

• Females and adolescents: Higher prevalence of thoracic spine pain 7
• Elderly patients: Lower threshold for imaging due to increased fracture and malignancy risk 1, 6
• Patients with prior spinal surgery: Early imaging warranted 1