Unexpected Giant Right Coronary Artery Aneurysm Diagnosed by Computed Tomography Angiography in the Emergency Department.

Giant coronary artery aneurysms (GCAA) are usually defined as diameter > 8 mm or > 400% of the adjacent normal segment; they are very rare (reported prevalence ≈0.02%). Though coronary angiography is the diagnostic gold standard, computed tomography angiography (CTA) offers a non-invasive, highly sensitive, and specific alternative. CTA enables detailed visualization of aneurysm morphology and detection of complications. We present the case of a 72-year-old man admitted to the Emergency Department with chest pain, where CTA played a crucial role in diagnosing a GCAA and assessing its potential life-threatening complications, highlighting its value in emergency cardiovascular imaging.