This patient's findings are consistent with several features of a syndrome described by Felson as CPVLS. Major components of CPVLS include hypogenetic lung, partial anomalous pulmonary venous return, absence of a pulmonary artery, pulmonary sequestration, systemic arterialization of the lung, absence of the inferior vena cava, and accessory diaphragm. Minor components of CPVLS include tracheal trifurcation, eventration and partial absence of the diaphragm, phrenic cyst, horseshoe lung, esophageal and gastric lung, anomalous superior vena cava, and absence of the pericardium.[1
] The primary feature of CPVLS is an abnormal drainage of a right pulmonary vein into the vena cava. This abnormal drainage course of the vein can often be seen on plain chest radiograph as a curvilinear density along the right heart border. Because this radiological sign resembles the Turkish sward, the anomaly was subsequently named the “scimitar syndrome.”[2
Traditionally, angiography has been used for imaging of pulmonary vascular anomalies, especially when pulmonary sequestration or scimitar syndrome is suspected.[3
] The objective is to identify the anomalous vessels (arteries and veins) in order to plan surgery and avoid accidental division or ligation. With advancement of CT technology, several studies have suggested the value of CT angiography as a noninvasive alternative in cases of pulmonary sequestration or CPVLS.[5
] More recently, the introduction of MDCT allows improved delineation of the complex and variable anatomic abnormalities seen in patients with CPVLS obviating the use of angiography or magnetic resonance angiography for diagnosis.[8
The clinical presentation of CPVLS is variable and depends mainly on the presence of associated cardiac anomalies and the potential development of pulmonary hypertension due to a large left to right shunt through the systemic arterial supply to the right lung. Some patients are symptomatic in the newborn period presenting with respiratory insufficiency and/or cardiac failure. Surgery is indicated for such patients and the success depends on the nature and severity of the underlying abnormalities.[9
] This case underwent pneumonectomy. On the contrary, some surgeons may recommend coil embolization (or surgical ligation) of the systemic arterial supply and re-routing of the anomalous vein to the left atrium. The aim is to conserve lung tissue and avoid the long-term issues of pneumonectomy in a young infant. However, in this infant, the right pulmonary artery was very tiny supplying only part of the upper lobe, and the main blood supply was from the systemic artery. So, the consequences of embolization or ligation of the systemic artery was unpredictable.
Another group of patients presents during young adulthood with recurrent pulmonary infections. The infections usually affect the right lower lobe which is most likely to be the site of pulmonary sequestration. These patients may require lobectomy or occasionally right pneumonectomy to prevent recurrent infections.[10
It is not uncommon to diagnose CPVLS as incidental finding in a chest radiograph. In such cases, due to absence of symptoms, these patients can be managed conservatively.
In summary, the term CPVLS is an umbrella to a group of pulmonary parenchymal and vascular anomalies that may present singly or in combination. The presence of any of these anomalies mandates search for the others. MDCT is an excellent diagnostic tool for delineation of the components of this syndrome.