Cannon-ball lesions are associated with which condition?

• A. Tuberculosis
• B. Sarcoidosis
• C. Metastatic lung cancer
• D. Pneumonia

Answer: (C)

Cannon-ball lesions are multiple, round, well-defined nodules in the lungs produced by tumor cells spreading hematogenously to the lung parenchyma. This classic pattern points to metastatic disease, where a primary cancer elsewhere seeds the lungs and forms several nodules of varying sizes.

TB can produce nodules, but they’re usually apical and may cavitate or show caseating granulomas rather than a uniform cannon-ball distribution. Pneumonia presents as lobar or segmental consolidation rather than multiple discrete nodules. Sarcoidosis can cause diffuse nodularity, but the pattern is typically along lymphatics with hilar lymphadenopathy, not the scattered cannon-ball nodules seen with metastases.