• Up to 1/3 of solitary nodules may be malignant.
• high-risk of malignancy: older patient age, positive smoking history, large size, evidence of metastatic disease, stippled or asymmetric/eccentric calcifications, irregular borders, avid uptake of fluorodeoxyglucose (FDG)
• Calcifications that usually indicate benign lesion - concentric calcification, uniform/diffuse dense calcification; central laminar
• popcorn calcifications = hamartomas;
• bull's-eye calcifications = granulomas

Evaluation of pulmonary nodule

• 1st step = look for prior (old) x-ray
• If no prior x-ray, do risk stratification
• Low-risk : <35 yr, non-smoker with calcified nodules
• can follow-up with repeat CXR or CT every 3 months for 2 years
• High-risk: >50 yr, smoker
• do open-lung biopsy and removal of the nodule at the same time

Workup of a CXR with an effusion and a nodule:

90% of tumors with malignant effusions are unresectable; and are mainly adenocarcinomas

Atelectasis on CXR suggests central airway obstruction