CT chest of a 65-year-old heavy smoker shows a 2.5 cm spiculated nodule in the right upper lobe with pleural tethering and a small satellite nodule. The PET-CT shows an SUVmax of 8.2. Which CT characteristic most independently predicts malignancy in a solitary pulmonary nodule?
- A Size > 2 cm
- B Upper-lobe location
- C Spiculation (corona radiata sign) ✓
- D Satellite nodule
Correct answer: C. Spiculation (corona radiata sign)
Explanation
Spiculation (corona radiata sign) — radiating linear strands from the nodule margin — is the single CT feature most independently associated with malignancy, reflecting tumour invasion of surrounding lymphatics and interstitium. While size > 2 cm and upper-lobe location increase risk, spiculation has the highest odds ratio. Satellite nodules may suggest malignancy but can also indicate granulomatous disease.
Reference: Grainger & Allison's Diagnostic Radiology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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