A 46-year-old man is brought to the emergency department by paramedics after an episode of large-volume hematemesis. He was going over some papers at work when he suddenly felt nauseated and started vomiting up bright red blood. Physical examination reveals a palpable spleen. Endoscopy shows bleeding esophageal varices. A liver biopsy performed 2 days later shows no abnormalities. Which of the following is the most likely cause of this patient's condition?
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This patient is exhibiting signs of portal hypertension, including esophageal varices and splenic enlargement. Varices form in portal hypertension due to increased hydrostatic pressure in the portal system that causes blood to be shunted through portocaval anastomoses. This patient's normal liver biopsy indicates that a presinusoidal process is responsible for the portal hypertension. Portal vein thrombosis causes obstruction in portal venous flow upstream to the liver, causing portal hypertension while not affecting the liver parenchyma. Ascites is uncommon with portal vein thrombosis since sinusoidal hypertension does not develop.
(Choice A) Acetaminophen toxicity causes centrilobular hepatic necrosis and liver failure 24-48 hours following ingestion, depending on the amount consumed. This process would be obvious on liver biopsy.
(Choice B) Long-term alcohol consumption can causes hepatic cirrhosis, which can cause portal hypertension. However, hepatocyte injury and fibrosis would be evident on liver biopsy. Mallory-Weiss tears can also occur with heavy alcohol use, however, mucosal lacerations (not varices) would be seen on endoscopy.
(Choice C) In Budd-Chiari syndrome, there is occlusion of the hepatic vein, which drains blood from the liver and portal circulation into the systemic circulation. Liver biopsy shows centrilobular congestion and fibrosis.
(Choice D) Constrictive pericarditis causes blood to back up in the systemic venous circulation due to decreased cardiac output. This increases pressure within the liver in much the same way as Budd-Chiari syndrome and would present with similar findings.
Educational objective:
Portal vein thrombosis causes portal hypertension, splenomegaly, and varicosities at portocaval anastomoses. It does not cause histologic changes to the hepatic parenchyma. Ascites is uncommon as the obstruction is presinusoidal; ascites typically only develops in conditions that cause sinusoidal hypertension.