Congenital Anomalous Azygos Vein Drainage Causing Pulmonary Embolus in a 91-Year-Old Patient

BACKGROUND: Retroaortic course and azygos continuation of aberrant left brachiocephalic vein is a rare venous anomaly, which is usually associated with congenital heart disease and pulmonary artery anomalies. Venous stasis is a cause of pulmonary arterial thromboembolism, which can result from venous anomalies. CASE PRESENTATION: We describe the case of a 91-year-old female admitted to our hospital with shortness of breath diagnosed with pulmonary embolism and infarctions by a CT pulmonary angiogram. CT also showed aberrant left brachiocephalic vein with vascular webs at its retroaortic course and azygos continuation, suggesting chronic venous thrombosis, which was considered to be the suspected source of emboli. CONCLUSION: To our knowledge, this is the first report presenting this vascular anomaly manifesting with chronic venous thrombosis and pulmonary embolism. Although rare, awareness and identification of this entity is important, especially in the absence of obvious embolic sources or in patients with recurrent embolus/consolidation. LEARNING POINTS: Awareness of congenital anomalous drainage anatomy is important even if there has been a relatively benign clinical course. Alterations in morphology due to age and degenerative change may result in altered flow predisposing to chronic embolic phenomena. Recurrent consolidation may not necessarily be due to infection in the elderly, a recurrent embolic phenomenon may also be a cause, in this case without a common cause such as deep vein thrombosis.