Clinical features of extrahepatic portal vein obstruction: Myeloproliferative neoplasms eliminate hypersplenic hematologic changes in extrahepatic portal vein obstruction.

Extrahepatic portal vein obstruction (EHPVO) is a rare disease. Most EHPVO patients are usually referred to a gastroenterologist for intestinal bleeding and hypersplenic thrombocytopenia; however, hypercoagulative diseases may be occult in these patients and require anticoagulation. The purpose of this study was to elucidate the clinical characteristics of EHPVO. We conducted a retrospective analysis of the hospital database, evaluating the medical records of 15 patients (7 males, 8 females, mean age of onset 42.0 years, range 5-74 years). Thirteen of 15 EHPVO patients (86.7%) had intestinal varices. These included 10 esophageal (66.7%), 12 gastric (80.0%), and 6 ectopic varices (40.0%). Nine (60.0%) of 15 had a history of intestinal bleeding. Regarding comorbidities, 5 of 15 (33.3%) suffered from vascular diseases, including acute myocardial infarction, cerebral infarction, pulmonary embolism, Budd-Chiari syndrome, and mesenteric vein thrombosis. The former 3 vascular commodities manifested at less than 32 years of age. Four patients (26.7%) with JAK2V617F mutation were diagnosed as myeloproliferative neoplasm (MPN). 72.3% of EHPVO patients without MPN experienced thrombocytopenic state. No EHPVO patients with MPN experienced thrombo-leukocytopenia. The elevation of white blood cell and platelet counts, and decrease of protein S were seen in EHPVO with MPN, compared with EHPVO without MPN. EHPVO is frequently associated with underlying hypercoagulative factors, causing a dilemma between thrombotic complications and portal hypertensive bleeding. Most EHPVO patients experience an evident thrombocytopenic state due to severe hypersplenism; however, hypersplenic hematologic changes are eliminated in EHPVO with MPN. MPN should be suspected in EHPVO patients negative for thrombo-leukocytopenia.