Differential Diagnosis for Low Stage Ascites with Portal Vein Dilatation

• Single most likely diagnosis
  • Cirrhosis: This is the most common cause of ascites and portal vein dilatation due to increased pressure in the portal vein from liver scarring, leading to fluid accumulation in the peritoneal cavity.
• Other Likely diagnoses
  • Portal Vein Thrombosis: A blood clot in the portal vein can cause portal hypertension, leading to ascites and dilatation of the portal vein.
  • Budd-Chiari Syndrome: This condition, characterized by thrombosis of the hepatic veins, can cause ascites and portal vein dilatation due to increased pressure in the liver.
  • Constrictive Pericarditis: This condition, where the pericardium becomes scarred and contracts, can impede blood flow back to the heart, leading to increased pressure in the portal vein and ascites.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Hepatic Artery Aneurysm: Although rare, a ruptured hepatic artery aneurysm can cause sudden onset of ascites and portal vein dilatation, and is life-threatening if not promptly treated.
  • Malignancy (e.g., Hepatocellular Carcinoma, Lymphoma): Certain cancers can cause ascites and portal vein dilatation, either by direct invasion of the portal vein or by causing cirrhosis.
• Rare diagnoses
  • Schistosomiasis: A parasitic infection that can cause liver fibrosis and portal hypertension, leading to ascites and portal vein dilatation.
  • Idiopathic Portal Hypertension: A rare condition of unknown cause that leads to increased pressure in the portal vein, resulting in ascites and portal vein dilatation.
  • Veno-occlusive Disease: A rare condition where the small hepatic veins are obstructed, leading to increased pressure in the liver and portal vein, causing ascites and portal vein dilatation.