Benign Dilatation of External Jugular Vein

Clinically: 
50 yo female with short stubby neck.

Nodular, compressible, pulsatile swellings in supraclavicular region on either side, pronounces in supine and subsides with standing.

Cardiac 2D Echo normal.

MRI Neck Axial T2w images

Findings are: 

Unusual dilatation and distention of anterior external jugular veins on either side thought out its course.
Left side internal jugular vein hypoplastic or absent.
Left side innominate vein appears to be compressed against sternum by mild anterior buckling of innominate artery. Right side anterior external jugular vein show abrupt angulation where it enters thoracic inlet.
No obvious superior mediastinal neoplastic mass or retro sternal thyroid.

Discussion:

Anterior external jugular veins on either side show normal course in neck running superficial and parallel to along posterior border of sternocleinoid mastoid and in subclavian triangle perforating the deep fascia and ends in the subclavian vein. Veins are normally provided with two pairs of valves, the lower pair being placed at its entrance into the subclavian vein, the upper in most cases about 4 cm above the clavicle. The portion of vein between these two sets of valves is often dilated, and is termed the sinus which is normal.
But in this case there is unusual dilatation and distention of veins thought out its course. Rest of the veins not dilated.
Appears to  be a benign finding as;
1.     Color Doppler study of internal jugular vein normal on right side. No obvious thrombosis.  Left side appears to be hypoplastic or absent may be significant in this case as caliber of anterior external jugular veins bears an inverse proportion with deep neck veins.
2.     Again left side innominate vein appears to be compressed against sternum by mild anterior buckling of innominate artery.
3.     Right side anterior external jugular vein show abrupt angulation where it enters thoracic inlet.
4.     Patient neck in addition is short and stubby.

Impression:

Unusual dilatation and distention of anterior external jugular veins on either side thought out its course – appears to be a benign finding of no clinical significance.