Figure 1: CT topogram demonstrates a well marginated soft tissue mass in the right hilum.

Figure 2: Axial CT image demonstrates a well circumscribed, lobulated, 2.1 x 2.8 cm soft tissue mass (arrow) adjacent to the right hilum, which appears to enhance to the same degree as the vessels in this area. This soft tissue mass abuts the right superior pulmonary vein.

Figure 3:

(3-A) Coronal time resolved image demonstrates the following anatomy:
SVC = Superior Vena Cava
MPA = Main Pulmonary Artery
RPA = Right Pulmonary Artery
LPA = Left Pulmonary Artery

(3-B) Coronal time resolved image demonstrates that the contrast bolus has circulated through the pulmonary circulation and is entering the left heart and aorta. Again noted is the well
circumscribed lobulated mass in the right hilar region.

(3-C) Coronal time resolved image demonstrates that the contrast bolus has passed into the peripheral circulation.

Figure 4: Axial contrast enhanced VIBE image demonstrates that the lobulated enhancing mass in the right hilar region (arrow) represents a torturous and dilated (approximately 2.4 cm) distal right inferior pulmonary vein.

Figure 5: Coronal MPR image again demonstrates that the lobulated enhancing mass in the right hilar region (arrow) represents a torturous and dilated distal right inferior pulmonary vein.

Pulmonary varix.

A pulmonary varix is a rare anomaly characterized as an aneurysmal dilation of a segment of pulmonary vein that has a normal entrance into the left atrium. Most cases have been described occurring secondary to pathologies that cause pulmonary venous hypertension, most frequently mitral valve stenosis and mitral valve insufficiency. Other proposed etiologies include a congenital or acquired focal weakness in the vein wall that results in dilatation with increased pulmonary venous pressures. A pulmonary varix is usually asymptomatic and most often presents as a well defined pulmonary or mediastinal mass on chest radiography. However, it can rarely present with hemoptysis or bronchial obstruction. Pulmonary varices have been classified based on their radiographic appearance into three subtypes: confluent, saccular, and tortuous.

The confluent type is a dilatation of the pulmonary vein at its entry into the left atrium, i.e. dilatation of the confluence of the pulmonary veins. This type of varix is commonly associated with mitral valvular disease, especially mitral valve insufficiency and stenosis. Most confluent type of varices involve the right pulmonary vein, with the inferior right pulmonary vein more commonly involved than the superior. The saccular type of pulmonary varix is a localized, oval shaped dilatation of the pulmonary vein. They are most frequently found in the right lower and left upper lobes. Saccular varices are most likely congenital lesions and have no association with cardiac disease. In addition, these types of varices have been shown to remain stable over many years. The tortuous type of pulmonary varix is an elongated, convoluted dilatation of the pulmonary vein. In many cases there is associated atresia or hypoplasia of one of the major pulmonary veins with drainage of the ipsilateral pulmonary venous flow via a single tortuous, dilated pulmonary vein, which empties into the left atrium. The inferior pulmonary vein is most often atretic and the superior vein dilated.

Pulmonary varices are most often an incidental finding on chest radiography where they may appear as a well-defined mass with a round, oval, or lobulated appearance. Although a pulmonary varix is a relatively benign lesion, it must be distinguished from other causes of mass lesions on chest radiography including neoplasm, granuolmatous disease, and a pulmonary arteriovenous malformation. On pulmonary angiography findings of a pulmonary varix include: (1) normal pulmonary arterial tree without dilatation; (2) the vein feeding the varix is seen in the venous phase and the varix fills at the same rate as the normal pulmonary vein; (3) the varix drains directly into the left atrium; (4) delayed emptying of the varix compared to other veins; (5) the varicose appearance and tortuous course affect only the proximal portion. Magnetic resonance imaging can diagnose a pulmonary varix by fulfilling criteria demonstrated via angiography including a normal pulmonary arterial tree and the connection between the feeding vein, varix, and the left atrium in multiple projections. MR angiography can further demonstrate flow between the pulmonary vein feeding the varix and the varix and the left atrium.

Pulmonary varices usually remain stable in the absence of pulmonary hypertension. Acute increases in varix size are indicative of elevation of left atrial pressure. Complications of pulmonary varices include rupture and thromboembolism. Treatment of these lesions is usually unnecessary once the correct diagnosis is established. Most varices secondary to pulmonary venous hypertension usually regress with correction of the pulmonary venous hypertension, e.g. mitral valve replacement in patients with mitral valve disease. In cases of hemoptysis in non-cardiac causes of the varix, pulmonary lobe resection can be necessary.

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