Portal Venous Obstruction

 Portal vein thrombosis

image Reduced portal flow velocity (stasis)

image Vascular injury

image Tumor thrombosis

image Extrinsic compression by mass or fibrogenic lesions

image Congenital vascular anomalies

• Intrahepatic
image Propagation of large portal vein thrombosis or emboli

image Diseases that affect small portal veins

image Specific etiology may not be identifiable

Clinical Issues

• 5-10% in patients with portal hypertension in developed countries

• Sequelae depend on location, cause, time course, and extent of blockage


• Often inconsistent or irregularly distributed, may be missed in biopsy specimens
• Subtle alterations of portal venules

image Dilated portal venules

image Multiple collateral venules

image Herniation of portal venules into parenchyma

image Obliteration of portal venules, similar to hepatoportal sclerosis, may be seen

• Infarcts of Zahn
image Persistent occlusion can lead to atrophy of entire segments of liver

image True infarcts rarely develop

• Nodular regenerative hyperplasia may be seen

• Findings suggestive of underlying etiologies

Top Differential Diagnoses

• Hepatoportal sclerosis

• Normal liver

Portal Vein Thrombosis
Gross photograph of this liver explant shows a large portal vein thrombus image in the hilar region. Propagation into smaller intrahepatic portal veins image is also grossly noticed.

Dilated Portal Venule
This microphotograph shows a markedly dilated portal venule image in the setting of portal vein thrombosis. Note the presence of fibrin thrombus in the lumen.

Herniated Portal Venule
Typical changes in portal venous obstruction include dilated portal venules with “herniation” of the vessel into the surrounding parenchyma. Note the presence of a bile duct image in compressed portal stroma.

Collateral Venules
Multiple collateral venules image are present in this portal tract in a case of portal venous obstruction indicating elevated portal pressures.



• Idiopathic portal hypertension
image Many cases of idiopathic portal hypertension probably represent undetected portal vein thrombosis

Only gold members can continue reading. Log In or Register to continue

Stay updated, free articles. Join our Telegram channel

Apr 20, 2017 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Portal Venous Obstruction

Full access? Get Clinical Tree

Get Clinical Tree app for offline access