{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,30]],"date-time":"2026-09-30T13:01:29Z","timestamp":1790773289681,"version":"4.1.0"},"reference-count":12,"publisher":"BMJ","issue":"9","content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Case Rep"],"accepted":{"date-parts":[[2026,9,16]]},"published-print":{"date-parts":[[2026,9]]},"abstract":"<jats:p>Splanchnic venous thrombosis (SVT) is a potentially catastrophic manifestation of polycythaemia vera (PV). We report a woman in her 60s with masked PV who had been managed for 5 years with intermittent phlebotomy and aspirin without haematology referral, molecular testing or cytoreductive therapy. Chronic iron deficiency masked erythrocytosis, delaying diagnosis. She presented with extensive thrombosis involving the portal, splenic and superior mesenteric veins complicated by mesenteric ischaemia requiring exploratory laparotomy, jejunal resection and ileostomy. Bone marrow biopsy and JAK2 V617F testing confirmed PV. Therapeutic anticoagulation was initiated with enoxaparin and subsequently transitioned to apixaban, while hydroxyurea achieved sustained haematologic control. Interval imaging demonstrated thrombus regression with persistent cavernous transformation. Given ongoing portal hypertension, oesophageal varices, occasional mild ostomy bleeding and low body weight, anticoagulation was continued indefinitely at reduced intensity with apixaban 2.5 mg twice daily. At 21-month follow-up, the patient remained free of recurrent thrombosis and major bleeding.<\/jats:p>","DOI":"10.1136\/bcr-2026-276448","type":"journal-article","created":{"date-parts":[[2026,9,30]],"date-time":"2026-09-30T12:45:27Z","timestamp":1790772327000},"page":"e276448","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":0,"title":["Masked polycythaemia vera presenting with extensive splanchnic venous thrombosis and mesenteric ischaemia"],"prefix":"10.1136","volume":"19","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-9789-620X","authenticated-orcid":false,"suffix":"Jr","given":"Rene A","family":"Amadore","sequence":"first","affiliation":[{"name":"Division of Hematology, Department of Medicine, Philippine General Hospital, Manila, Philippines"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jerome A","family":"Anopol","sequence":"additional","affiliation":[{"name":"Division of Hematology, Department of Medicine, Philippine General Hospital, Manila, Philippines"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Deonne Thaddeus V","family":"Gauiran","sequence":"additional","affiliation":[{"name":"Division of Hematology, Department of Medicine, Philippine General Hospital, Manila, Philippines"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"239","published-online":{"date-parts":[[2026,9,30]]},"reference":[{"key":"2026093005451933000_19.9.e276448.1","doi-asserted-by":"crossref","first-page":"1465","DOI":"10.1002\/ajh.27002","article-title":"Polycythemia vera: 2024 update on diagnosis, risk\u2010stratification, and management","volume":"98","author":"Tefferi","year":"2023","journal-title":"American J Hematol"},{"key":"2026093005451933000_19.9.e276448.2","doi-asserted-by":"publisher","DOI":"10.1200\/JCO.2005.07.062"},{"key":"2026093005451933000_19.9.e276448.3","doi-asserted-by":"publisher","DOI":"10.1002\/hep.21435"},{"key":"2026093005451933000_19.9.e276448.4","doi-asserted-by":"publisher","DOI":"10.1182\/blood-2008-12-196014"},{"key":"2026093005451933000_19.9.e276448.5","doi-asserted-by":"publisher","DOI":"10.3324\/haematol.12053"},{"key":"2026093005451933000_19.9.e276448.6","doi-asserted-by":"publisher","DOI":"10.1182\/blood-2014-07-551515"},{"key":"2026093005451933000_19.9.e276448.7","doi-asserted-by":"publisher","DOI":"10.1182\/blood.2024025627"},{"key":"2026093005451933000_19.9.e276448.8","doi-asserted-by":"crossref","first-page":"364","DOI":"10.1097\/MBC.0000000000001388","article-title":"Indefinite anticoagulation with reduced-intensity direct oral anticoagulants in patients with splanchnic vein thrombosis. An international practice survey","volume":"36","author":"Delluc","year":"2025","journal-title":"Blood Coagul Fibrinolysis"},{"key":"2026093005451933000_19.9.e276448.9","doi-asserted-by":"crossref","DOI":"10.1038\/s41408-018-0151-y","article-title":"Hydroxyurea prevents arterial and late venous thrombotic recurrences in patients with myeloproliferative neoplasms but fails in the splanchnic venous district. Pooled analysis of 1500 cases","volume":"8","author":"De Stefano","year":"2018","journal-title":"Blood Cancer J"},{"key":"2026093005451933000_19.9.e276448.10","doi-asserted-by":"crossref","first-page":"156","DOI":"10.1002\/ajh.25677","article-title":"Splanchnic vein thromboses associated with myeloproliferative neoplasms: An international, retrospective study on 518 cases","volume":"95","author":"Sant\u2019Antonio","year":"2020","journal-title":"Am J Hematol"},{"key":"2026093005451933000_19.9.e276448.11","doi-asserted-by":"publisher","DOI":"10.1056\/NEJMoa1207541"},{"key":"2026093005451933000_19.9.e276448.12","doi-asserted-by":"publisher","DOI":"10.1016\/S0140-6736(24)02842-3"}],"container-title":["BMJ Case Reports"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1136\/bcr-2026-276448","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,30]],"date-time":"2026-09-30T12:45:28Z","timestamp":1790772328000},"score":1,"resource":{"primary":{"URL":"https:\/\/casereports.bmj.com\/lookup\/doi\/10.1136\/bcr-2026-276448"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,9]]},"references-count":12,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2026,9,30]]},"published-print":{"date-parts":[[2026,9]]}},"alternative-id":["10.1136\/bcr-2026-276448"],"URL":"https:\/\/doi.org\/10.1136\/bcr-2026-276448","relation":{},"ISSN":["1757-790X"],"issn-type":[{"value":"1757-790X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,9]]}}}