Case Report: Autoimmune hepatitis following oxaliplatin exposure presenting with multifactorial non-cirrhotic portal hypertension and recurrent parastomal variceal bleeding.

Ectopic variceal hemorrhage accounts for approximately 5% of all variceal bleeding episodes and represents an uncommon manifestation of portal hypertension. This report describes recurrent parastomal variceal bleeding in a 43-year-old woman with rectal adenocarcinoma who underwent abdominoperineal resection followed by five cycles of oxaliplatin-containing chemotherapy. During chemotherapy, severe hepatocellular injury developed. A liver biopsy performed in June 2020 demonstrated severe interface hepatitis with lymphoplasmacytic portal inflammation, findings that supported a diagnosis of autoimmune hepatitis (AIH). No histopathological features diagnostic of portosinusoidal vascular disease (PSVD) were identified. Subsequently, progressive splenomegaly, gastroesophageal and parastomal varices, and a directly measured portal pressure of 35 cm H2O developed in the absence of established cirrhosis. Inferior mesenteric vein embolization and ultrasound-guided foam sclerotherapy reduced the frequency of recurrent parastomal variceal bleeding but did not achieve complete hemostatic control. Treatment with carvedilol and prednisone was subsequently initiated. The overall clinical presentation was most consistent with multifactorial non-cirrhotic portal hypertension associated with AIH and prior oxaliplatin exposure, with a potential contribution from oxaliplatin-associated sinusoidal or vascular liver injury rather than histologically confirmed PSVD. This case highlights the diagnostic complexity and the need for individualized management in individuals with coexisting autoimmune liver disease, chemotherapy-associated hepatic injury, and refractory ectopic variceal hemorrhage.