Extrahepatic portal vein obstruction (EHPVO) is a very rare disease-causing portal hypertension. Myeloproliferative neoplasm (MPN) including essential thrombocythemia (ET) is reported as a risk factor for EHPVO due to underlying persistent thrombophilia.A Japanese woman in her 40s was referred to our hospital with a one-month history of gastric variceal bleeding due to EHPVO. Laboratory investigation demonstrated thrombocytosis despite portal hypertension. She had a mutation of clonal marker JAK2V617F with EHPVO, which prompted us to consult a hematologist. Bone marrow biopsy revealed megakaryocyte lineage proliferation, leading to a diagnosis of ET.Esophagogastroduodenoscopy indicated esophagogastric varices (LsF2CbRC2, Lg-cF1RC1). Abdominal Computed Tomography and angiography revealed splenomegaly and portal vein thrombosis with cavernous transformation. These radiologic findings suggested EHPVO.The patient had a history of ruptured esophagogastric varices and required prophylaxis against further variceal bleeding prior to anti-thrombotic therapy for EHPVO with ET. We performed laparoscopic Hassab's operation followed by endoscopic variceal ligation (EVL) and hematological cytoreduction therapy.Laparoscopic Hassab's operation and three bi-monthly EVL improved the esophagogastric varix (LmF0RC0, Lg-f F0RC0) at 6 months after surgery. Platelet count decreased to 60.1 x104 /uL by cytoreduction therapy. She was very healthy at 7 months after surgery.Patients with EHPVO are traditionally referred to the gastroenterologist for abdominal pain, intestinal bleeding, or refractory ascites; however, hypercoagulative disease may be occult in such patients and require the attention of a hematologist. When encountering the patients with splanchnic thrombosis caused by EHPVO, the gastroenterologists should screen for hematological disease, including MPN.
Keywords: JAK2V617F mutation; esophagogastric varices; essential thrombocythemia; extrahepatic portal vein obstruction; laparoscopic Hassab's operation.