Internal jugular vein aneurysm in an adult: diagnosis on non-invasive imaging

Abstract

We report the case of a 48-year-old man with a right fusiform internal jugular venous aneurysm, presenting as a unilateral painless neck swelling on coughing or laughing. This is a rare condition, more commonly seen in the paediatric population and can be diagnosed using non-invasive modalities such as Doppler ultrasound and contrast-enhanced CT. This anomaly is frequently misdiagnosed or overlooked, and our case highlights the importance of considering venous aneurysm as a differential to prevent invasive imaging and inappropriate management.

Background

Internal jugular vein (IJV) aneurysm, also known as internal jugular phlebectasia, is very rare and is usually described in the paediatric population. A PubMed search of English literature identified less than 40 cases reported in adults. The exact aetiology is unclear but it is thought to run a benign course.

The diagnosis may be difficult due to the rarity of this condition and result in unnecessary investigations. Our case highlights the importance of maintaining a high index of suspicion in order to avoid invasive imaging.

Case presentation

A 48-year-old man described a 5-year history of painless right neck swelling. He reported it was gradually increasing in size, especially on laughing and coughing. However, there was no change in voice, difficulty swallowing or breathing. He previously had a traumatic liver injury 20 years ago requiring hepatic artery embolisation, with subsequent portal vein thrombosis and portal hypertension following the trauma. He was not aware of any trauma or instrumentation to his right neck.

On examination, he had a soft, compressible, non-tender and non-pulsatile right neck mass. It extended from below the right sternocleidomastoid muscle into the posterior triangle and measured 3 cm in diameter by 4 cm in length. The mass increased in size with the Valsalva manoeuvre to 4×7 cm (figure 1). It was not possible to get below the swelling, and there were no associated skin changes or bruit.

Figure 1.

Appearance of right internal jugular vein aneurysm at rest (A) and during the Valsalva manoeuvre (B).

Investigations

Doppler ultrasound revealed a dilated right jugular vein with no evidence of thrombus (figure 2). Subsequent contrast-enhanced CT (CECT) of the neck and thorax revealed a fusiform aneurysmal dilatation of the right IJV measuring 3.4×7.2×4.3 cm extending from the level of C3 to the level of confluence with the right subclavian vein (figure 3). There was no intraluminal thrombus, and the left IJV was normal in calibre. It remained unchanged in size on a CECT of the neck a year later. With regard to a possible underlying cause, there was no mediastinal mass seen, and transthoracic echocardiogram did not show any evidence of heart failure.

Figure 2.

Ultrasound image of dilated right internal jugular vein adjacent to common carotid artery.

Figure 3.

Contrast-enhanced CT images in axial (A), coronal (B) and sagittal (C) planes showing fusiform aneurysmatic dilatation of right internal jugular vein.

Differential diagnosis

Differential diagnosis for a neck mass accentuated by the Valsalva manoeuvre include laryngocele (most common),¹ external laryngeal diverticulae, superior mediastinal cyst or tumour and pneumocele.^{2 3}

Outcome and follow-up

As the patient was asymptomatic and the right IJV phlebectasia had remained stable in size, decision for conservative management and surveillance was made.

Discussion

Phlebectasia describes a fusiform or saccular dilatation of a vein.⁴ It has been reported in all neck veins; the highest frequency in the IJVs, followed by external jugular and anterior jugular veins.⁵

IJV phlebectasia commonly presents in childhood and is rarely reported in adults. It usually presents as a painless neck swelling that increases in size with the Valsalva manoeuvre. In cases of IJV dilatation, the jugular vein is likely to be incompetent, hence resulting in an enlargement of the venous aneurysm with increased intrathoracic pressure. It has a right-sided predominance,⁶ as presented here, possibly due to direct continuity of the right IJV with the right brachiocephalic vein and a larger right inferior jugular bulb.^{1 7}

The exact aetiology of IJV phlebectasia is however unknown, with suggested underlying causes including congenital venous wall defect, trauma, inflammation or mechanical compression.^{8 9} Histopathological findings vary; some show a normal pattern whereas some demonstrate a loss or disordered arrangement of smooth muscle cells and elastic fibres.^{8 10}

Phlebectasia can be identified on non-invasive imaging such as ultrasonography, CECT or MR venography. Ultrasound with colour Doppler imaging is thought to be first-line as it offers assessment of the relation to other neck structures, dynamic evaluation of increase in size of the vein during the Valsalva manoeuvre and detection of the presence of thrombus.⁵ CECT has the advantage of identifying deeper neck anatomy and any intrathoracic masses that may cause mechanical compression. It would also demonstrate intraluminal thrombus as a filling defect.

IJV aneurysms are generally benign, with the majority of surgical interventions performed for cosmetic reasons. In some cases, no complications were found even after 4 years of follow-up.^{11 12}

Complications have been reported in a very small number of cases. Enlarging IJV aneurysms have been described to cause discomfort necessitating surgery.^{13 14} Thrombosis, presenting as increasing neck pain, has also been found.^{15 16} There has been a single report of thrombophlebitis (associated fever and vomiting) and one case presenting as a Horner’s syndrome.^{17 18}

Pulmonary embolism (PE) has been described in popliteal and femoral vein aneurysms,^{11 12} however we did not find any cases of PE secondary to IJV aneurysms and a single case secondary to a thrombosed external jugular vein aneurysm.¹⁹ Although surgery has been undertaken in a number of cases due to concerns regarding risk of rupture,^{12 20} no cases of spontaneous rupture have been reported.

Surgery is hence not usually recommended in asymptomatic patients, and they should be managed conservatively and followed up for potential complications.^{12 21} Some authors however advocate treatment for saccular aneurysms, due to a possibly higher risk of thrombus or rupture.^{22 23}

Learning points.

• Internal jugular vein aneurysm or phlebectasia is a rare cause of neck swelling, especially in adults.

• First-line imaging is with Doppler ultrasound during the Valsalva manoeuvre.

• Contrast-enhanced CT may reveal possible underlying causes such as compression from mediastinal mass.

• It is usually benign and does not require surgical intervention if asymptomatic.