Portal Vein Obstruction

Epidemiology and Etiology:

• Acute obstruction:
• May occur in setting of abdominal sepsis
• Trauma
• Cirrhosis
• HCC growth into main portal vein
• Chronic:
• Thrombosis is most frequent mechanism
• Usually secondary to obstruction,
1. Cirrhosis
2. Tumour in the hepatic hilum or pancreas
3. Early PBC (small portal vein disease)
• Venous inflammation,
1. PSC (hilar bile leak)
2. Post-transplant
3. Splanchnic sepsis
4. Variceal scleropathy
5. Trauma
1. Blunt abdominal injury
2. Surgery complication
• Or a hypercoagulable state
1. Inherited clotting abnormalities
2. Platelet abnormalities
1. Polycythemia vera
2. Other myeloproliferative diseases
• Thrombosis of small portal veins:
1. Inflammation in the portal tracts from any chronic disease

Common sites:

Gross features:

• Chronic portal vein obstruction:
• Portal vein thrombosis usually
• May be recanalized to any extent
• Cavernous transformation maybe
• Thrombosis with multiple recanalized channels
• Absent or hypoplastic portal vein maybe
• Persistent ductus venosus
• Multiple local collaterals of portal vein to other veins
• Renal vein
• Adrenal vein
• Umbilical via round ligament
• Aneurismal dilatation of portal vein maybe
• Cirrhosis commonly
• Varices
• Splenomegaly
• Ascites is usually absent
• Acute portal vein obstruction:
• Thrombosis of portal vein
• Thrombosis of mesenteric veins
• Infarction of the intestines

Histologic features:

• Atrophy of involved liver parenchyma
• Uniform or mixed in a nodular regenerative hyperplasia pattern

Immunophenotype:

Marker:

Sensitivity:

Specificity:

Molecular features:

Other features:

• Thrombocytopenia
• Hyperammonemia with portosystemic shunting
• clinical features
• hepatic encephalopathy with portosystemic shunting

References:

• Odze RD, ed. (2004) Surgical Pathology of the GI Tract, Liver, Biliary Tract, and Pancreas.