[The 491st case: thrombocytosis, gastrointestinal hemorrhage, intestinal perforation].

Essential thrombocythemia (ET) is a chronic myeloproliferative neoplasm (MPN) featured by clonal proliferation of platelets, thrombosis and hemorrhage. Portal hypertension is a serious complication of ET associated with poor prognosis. We report a patient with ET complicated with acute upper gastrointestinal hemorrhage and intestinal perforation due to portal hypertension. She had an uneventful recovery after surgical and endoscopic treatment.