Azygos Continuation of the Inferior Vena Cava: Potential for Misdiagnosis as Lung Neoplasm.

BACKGROUND: The azygos venous system is an accessory venous pathway supplying an important collateral circulation between the superior and inferior vena cava (IVC). CASE
SUMMARY: We report a case of complicated community-acquired pneumonia with interruption of the IVC with azygos continuation that was misdiagnosed as lung neoplasm. DISCUSSION: The aim of this case report is to emphasize the importance of recognizing an enlarged azygos vein at the confluence with the superior vena cava and in the retrocrural space to avoid misdiagnosis as a right-sided para-tracheal mass. The angiographic features and clinical importance of this condition are discussed. LEARNING POINTS: An enlarged azygos vein at the confluence with the superior vena cava and in the retrocrural space can be misdiagnosed as a right-sided para-tracheal mass/neoplasm or retrocrural adenopathy.Biopsy is the most important tool to confirm the diagnosis of malignancy but could be catastrophic in this situation.Re-imaging after treatment for infection and pneumonia could potentially avoid this error. © EFIM 2021.