How can I rule out a Pancoast tumor in a patient with symptoms?

Diagnostic Approach to Rule Out Pancoast Tumor

To rule out a Pancoast tumor in a 66-year-old female patient with suspicious symptoms, a comprehensive diagnostic workup including tissue diagnosis, MRI of the thoracic inlet, and invasive mediastinal staging is recommended.

Clinical Presentation to Consider

• Most Pancoast tumors present with shoulder or chest wall pain radiating toward the axilla, scapula, and/or along the ulnar distribution of the upper arm 1, 2
• Neurological findings may include radicular pain or sensory changes in the ulnar hand due to invasion of the lower brachial plexus (C8-T1) 1, 3
• Horner syndrome (ptosis, miosis, anhidrosis) may be present due to invasion of the stellate ganglion 1, 3
• Hand swelling may indicate subclavian or brachiocephalic vein compression 1
• Atrophy of hand and arm muscles may be present in advanced cases 2

Diagnostic Algorithm

Step 1: Initial Imaging

• Chest radiographs may only show subtle apical pleural thickening as tumors can hide behind the first rib 1
• CT scan of the chest is essential to detect small lesions and provide anatomic detail 1, 4
• CT scan may miss isoattenuating tumors (5-17% of cases) 1

Step 2: Advanced Imaging

• MRI of the thoracic inlet and brachial plexus is recommended to:
  • Better characterize possible tumor invasion of vascular structures or extradural space 1
  • Evaluate invasion of apical chest wall structures, particularly the brachial plexus 1
  • Accurately predict tumor resectability 5

Step 3: Tissue Diagnosis

• A tissue diagnosis must be obtained prior to initiating any therapy 1
• CT-guided transcutaneous needle biopsy is the preferred method for diagnosis 1, 3
• Transbronchial biopsy is less useful as these lesions are usually peripheral 1

Step 4: Staging Workup

• Invasive mediastinal staging is recommended for all patients being considered for curative resection 1
• Extrathoracic imaging should include:
  • Head CT/MRI 1
  • Either whole-body PET or abdominal CT plus bone scan 1
• PET-CT can be considered for staging in the presence of non-metastatic disease on CT 1

Important Considerations

• Pancoast tumors are classified as T3 when they invade the T1 or T2 nerve roots or first rib, and T4 when there is involvement of C8 or higher nerve roots, brachial plexus cords, subclavian vessels, vertebral bodies, or laminae 3
• Most Pancoast tumors are non-small cell lung cancers, with adenocarcinomas accounting for approximately two-thirds of cases 2
• Invasion of the subclavian vessels, mediastinum, or vertebral bodies may contraindicate surgery 4
• Involvement of mediastinal nodes and/or metastatic disease represents a contraindication to resection 1

Treatment Implications

• For potentially resectable tumors with good performance status, preoperative concurrent chemoradiotherapy followed by surgical resection is suggested 1, 3
• For unresectable, non-metastatic tumors with good performance status, definitive concurrent chemotherapy and radiotherapy are suggested 1
• For patients who are not candidates for curative-intent treatment, palliative radiotherapy is suggested 1

Pitfalls to Avoid

• Relying solely on chest radiographs, which may miss early lesions 1, 4
• Failing to obtain a tissue diagnosis before initiating treatment 1
• Overlooking the need for invasive mediastinal staging even when CT or PET scans do not suggest mediastinal node involvement 1
• Misdiagnosing symptoms as musculoskeletal in origin, particularly in patients with risk factors for lung cancer 6