The azygos vein courses on the right paravertebral aspect posterior to the IVC and drains the posterior thorax, until it courses over the right tracheobronchial groove and empties into the posterior SVC; it is an important connection between the SVC and IVC. In patients with cirrhosis and portal hypertension, variceal dilation results in portosystemic collaterals, which may include a rare spontaneous portoazygos shunt with resultant dilation 1.
This case was submitted with supervision and input from:
Soni C. Chawla, M.D. Associate Professor Department of Radiological Sciences David Geffen School of Medicine at UCLA Olive View - UCLA Medical Center