Aids in Diagnosis of Malignancy

• Patient age
  • < 45 yr: low risk
  • > 60 yr: high risk
  • Cigarette smoking
    • Never smoked: low risk
    • Current smoker: high risk

• < 1.5 cm: low risk
• ≥ 2.3 cm: high risk

Pattern of Lesion Margin

• Corona radiata (fine strands extending from lesion): high risk
• Scalloped margins: intermediate risk
• Smooth border: low risk

• Stippled or eccentric calcification: high risk
• Laminated or central calcification: granuloma
• “Popcorn” calcification: hamartoma

• Old chest radiographs, CT scans reveal stability or growth
• 30% increase in diameter = doubling of volume
• Doubling in volume over > 1 mo and < 1 yr indicates malignancy
• Stability for 2 years = benign in 65%
• Follow-up imaging every 3 mo for 1 yr, then every 6 mo
  • CT can detect changes in size within 30 days

Noninvasive Diagnostic Methods

• Lesions with greater density more likely benign
• Lesion must be compared with a “phantom” for density calibration
• Cutoff points: 185–264 Hounsfield units

• Enhancement of lesion of > 20 Hounsfield units
• Sensitivity, 95%–100%; specificity, 70%–93%

• Differentiates benign from malignant nodules
• Sensitivity, 97%; specificity, 78%
• False positives: infectious, inflammatory lesions
• False negatives: bronchoalveolar carcinoma, carcinoids, nodules < 1 cm
• Can provide information for staging

Invasive Diagnostic Methods

• Very poor yield with lesions < 1.5 cm
• 40%–60% yield with lesions 2.5–3 cm
• Enhanced yield with lesions close to bronchus

• > 90% sensitivity for malignant lesions > 2 cm
• Significant false negative rate with smaller, centrally located lesions

• Video-assisted thoracic surgery for established or suspected malignancy in patients at low surgical risk

Best Therapy