Chest Medicine













Solitary Pulmonary Nodules
  • Common incidental finding on CXR
  • May be entirely symptomatic or may present with cough and dyspnoea
  • May be associated with smoking and second-hand smoking → increased risk of lung cancer

Investigation
  • Consider CT chest as the next investigation
    • If the nodule has fat or calcification characteristic of a benign lesion (hamartoma or granuloma) → no further evaluation required
    • If reassuring features are absent → review previous CT if available
      • If old CT available, nodule old AND no progression in size over 2 years → no further evaluation required
      • If old CT not available OR progression in size OR new nodule → determine risk of malignancy

Risk Stratification for Lung Nodules
FeatureLow RiskIntermediate RiskHigh Risk
Diameter (cm)< 0.80.8-2≥ 2
Age (years)< 4545-60≥ 60
Smoking StatusNeverYesYes
Years since smoking cessation (if applicable)> 155-15< 5
Nodule characteristics on CTSmoothScallopedCorona radiata or spiculated

Characteristics of benign and malignant lung nodules
BenignMalignant
Age < 35 years> 45-50 years of age
Non-smokerSmoker
No change from old filmsNew or enlarging lesions
Central, uniform or popcorn calcificationAbsent or irregular calcification
Smooth marginsIrregular margins (scalloped or spiculated)
Size < 2 cmSize ≥ 2 cm

Chest X-ray showing a solitary pulmonary nodule (indicated by a black box) in the left upper lobe (courtesy of wikipedia.org)

Management
  • Low risk: serial CT scans
  • Intermediate risk: biopsy or PET
  • High risk: surgical excision

Reference: First-Aid for the USMLE step 2 CK (10th Edition)