Incidental meandering right pulmonary vein, literature review and proposed nomenclature revision

Abstract

We report a case of an anomalous pulmonary vein on chest X-ray resembling a scimitar sign in an 80-year-old female undergoing investigation of syncope. Multislice computed tomography (CT) with multiplanar reformatting and maximum intensity projections demonstrated an aberrant right inferior pulmonary vein coursing inferomedially towards the diaphragm before turning superiorly and draining normally into the left atrium. The diagnosis of an incidental meandering right pulmonary vein was established. The case is used to review the literature on this rare pulmonary anomaly, including pathogenesis, its relationship with scimitar syndrome and scimitar variant, and diagnosis, with an emphasis on the role modern CT techniques can play in non-invasive diagnosis. A revision to the nomenclature of pulmonary vascular anomalies is proposed to help reduce confusion in the literature.

Meandering right pulmonary vein associated with severe and progressive “idiopathic-like” pulmonary hypertensive vascular disease

“…Anomalies involved in this syndrome may appear in isolation or in combination, and thus the clinical presentation of this syndrome is variable, depending mainly on the presence of associated cardiac abnormalities. [1][2][3][4][5] "Scimitar syndrome", described in 1960, consists of variable combinations of hypoplasia of the right lung and right pulmonary artery, dextroposition of the heart, anomalous arterial supply to the right lower lobe, and anomalous pulmonary venous drainage of the right lung into the inferior caval vein 4 causing the characteristic "scimitar sign"a Turkish sword-shaped shadow along the right heart border on chest X-ray. Infant forms, presenting with respiratory insufficiency, heart failure, or pulmonary hypertension, are usually associated with systemic arterial supply (sequestrum), severe right lung hypoplasia, and abnormal drainage of the right pulmonary vein into the inferior caval vein.…”

“…structures are rare. A varied spectrum of pathologies has been described [1][2][3][4][5] within the syndrome called "congenital pulmonary venolobar syndrome". Pseudo-scimitar syndrome, or "meandering" right pulmonary vein, consists of an anomalous right pulmonary vein, which takes a tortuous route through the lung, but terminates with normal drainage into the left atrium.…”

“…Although meandering right pulmonary vein has been described in some cases with an association with right lung hypoplasia, it is often an incidental finding. 3 In the Panama classification of Paediatric Hypertensive Pulmonary Vascular Disease, 6 pulmonary vein anomalies were considered to be a part of pulmonary hypertensive vascular disease associated with CHD. In the National Institute for Health and Care Excellence updated classification, 7 pulmonary hypertensive vascular disease associated with abnormalities in lung development was included in group IIIpulmonary hypertension associated with lung disease or hypoxia.…”

Scimitar sign: Anomalous pulmonary venous drainage

“… The term ‘meandering right pulmonary vein’ was coined by Goodman et al to describe the presence of the scimitar sign and an anomalous right pulmonary vein that drains normally into the left atrium A scimitar variant describes the connection of an anomalous right pulmonary vein to both the IVC and left atrium …”

Congenital bronchopulmonary vascular malformations, "sequestration" and beyond

“…Initially, scimitar sign was thought to be specific for scimitar syndrome; subsequently, however, a number of pulmonary venous anomalies like anomalous meandering pulmonary vein, anomalous unilateral single pulmonary vein (AUSPV), and scimitar variant were found to show a similar scimitar sign. [ 8 9 10 ] Further, these scimitar variants can be associated with abnormalities of pulmonary airways (e.g. meandering pulmonary vein and pulmonary hypoplasia).…”