{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,14]],"date-time":"2026-04-14T15:54:15Z","timestamp":1776182055547,"version":"3.50.1"},"reference-count":10,"publisher":"BMJ","issue":"4","content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Case Rep"],"accepted":{"date-parts":[[2026,3,31]]},"published-print":{"date-parts":[[2026,4]]},"abstract":"<jats:p>Splanchnic vein thrombosis (SVT) is a rare, life-threatening condition that is often associated with cirrhosis, pancreatic malignancy and thrombophilia. Myeloproliferative neoplasms are under-recognised causes, posing diagnostic challenges. In this case, we present a male in his late 20s with a history of unprovoked pulmonary embolism and portal\/splenic vein thrombosis, on indefinite anticoagulation therapy presenting 3 years later due to abdominal pain. Imaging revealed cirrhosis, cavernous transformation of the main portal vein and splenomegaly. These findings and a prior negative hypercoagulability workup prompted haematology consultation. Bone marrow biopsy confirmed primary myelofibrosis (PMF), demonstrating 90% cellularity, megakaryocytic hyperplasia, MF-3 fibrosis and calreticulin (CALR) mutation. This case underscores PMF as a treatable cause of SVT in young patients with recurrent thrombosis and highlights the consequences of diagnostic inertia, as marked thrombocytosis at initial presentation was overlooked. When Janus Kinase 2 (JAK2) is negative, CALR testing should be pursued to enable early diagnosis and targeted therapy.<\/jats:p>","DOI":"10.1136\/bcr-2025-271608","type":"journal-article","created":{"date-parts":[[2026,4,14]],"date-time":"2026-04-14T14:55:22Z","timestamp":1776178522000},"page":"e271608","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":0,"title":["Myeloproliferative neoplasm as a cause of splanchnic vein thrombosis"],"prefix":"10.1136","volume":"19","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-5288-5934","authenticated-orcid":false,"given":"Brian","family":"Abboud","sequence":"first","affiliation":[{"name":"Internal Medicine, SSM Health Saint Louis University Hospital, St. Louis, Missouri, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Isra","family":"Taha","sequence":"additional","affiliation":[{"name":"Internal Medicine, SSM Health Saint Louis University Hospital, St. Louis, Missouri, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ziniya","family":"Shah","sequence":"additional","affiliation":[{"name":"School of Medicine, SSM Health Saint Louis University Hospital, St. Louis, Missouri, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Allison","family":"Shildt","sequence":"additional","affiliation":[{"name":"Internal Medicine, SSM Health Saint Louis University Hospital, St. Louis, Missouri, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ariel","family":"Rischall","sequence":"additional","affiliation":[{"name":"Division of Hematology-Oncology and Bone Marrow Transplant, SSM Health Saint Louis University Hospital, St. Louis, Missouri, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Joseph","family":"Wheeler","sequence":"additional","affiliation":[{"name":"Internal Medicine, SSM Health Saint Louis University Hospital, St. Louis, Missouri, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"239","published-online":{"date-parts":[[2026,4,14]]},"reference":[{"key":"2026041407551153000_19.4.e271608.1","doi-asserted-by":"crossref","DOI":"10.1371\/journal.pone.0141010","article-title":"Calreticulin Mutations in Myeloproliferative Neoplasms: Comparison of Three Diagnostic Methods","volume":"10","author":"Park","year":"2015","journal-title":"PLoS ONE"},{"key":"2026041407551153000_19.4.e271608.2","doi-asserted-by":"crossref","first-page":"240","DOI":"10.1160\/th15-04-0326","article-title":"Splanchnic vein thrombosis and myeloproliferative neoplasms: molecular-driven diagnosis and long-term treatment","volume":"115","author":"Stefano","year":"2016","journal-title":"Thromb Haemost"},{"key":"2026041407551153000_19.4.e271608.3","doi-asserted-by":"publisher","DOI":"10.1182\/blood-2011-09-376517"},{"key":"2026041407551153000_19.4.e271608.4","doi-asserted-by":"publisher","DOI":"10.1182\/blood-2009-08-238956"},{"key":"2026041407551153000_19.4.e271608.5","doi-asserted-by":"publisher","DOI":"10.1056\/NEJMoa1311347"},{"key":"2026041407551153000_19.4.e271608.6","doi-asserted-by":"publisher","DOI":"10.1016\/j.chest.2015.11.026"},{"key":"2026041407551153000_19.4.e271608.7","doi-asserted-by":"publisher","DOI":"10.1182\/blood-2016-03-643544"},{"key":"2026041407551153000_19.4.e271608.8","doi-asserted-by":"publisher","DOI":"10.1182\/blood-2007-11-125328"},{"key":"2026041407551153000_19.4.e271608.9","doi-asserted-by":"publisher","DOI":"10.1111\/j.1538-7836.2006.02277.x"},{"key":"2026041407551153000_19.4.e271608.10","doi-asserted-by":"publisher","DOI":"10.1016\/j.mayocp.2017.06.002"}],"container-title":["BMJ Case Reports"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1136\/bcr-2025-271608","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,4,14]],"date-time":"2026-04-14T14:55:22Z","timestamp":1776178522000},"score":1,"resource":{"primary":{"URL":"https:\/\/casereports.bmj.com\/lookup\/doi\/10.1136\/bcr-2025-271608"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,4]]},"references-count":10,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2026,4,14]]},"published-print":{"date-parts":[[2026,4]]}},"alternative-id":["10.1136\/bcr-2025-271608"],"URL":"https:\/\/doi.org\/10.1136\/bcr-2025-271608","relation":{},"ISSN":["1757-790X"],"issn-type":[{"value":"1757-790X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,4]]}}}