{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,5]],"date-time":"2026-02-05T10:41:19Z","timestamp":1770288079013,"version":"3.49.0"},"reference-count":12,"publisher":"S. Karger AG","issue":"2","license":[{"start":{"date-parts":[[2017,7,11]],"date-time":"2017-07-11T00:00:00Z","timestamp":1499731200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"},{"start":{"date-parts":[[2017,7,11]],"date-time":"2017-07-11T00:00:00Z","timestamp":1499731200000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Case Rep Oncol"],"abstract":"<b><i>Background:<\/i><\/b> Erdheim-Chester disease (ECD) is a rare non-Langerhans cell histiocytosis disorder that utilizes the RAS-RAF-MEK-ERK pathway. It has a highly variable clinical presentation, where virtually any organ can be involved, thus having the potential of posing a great diagnostic challenge. Over half of the reported cases have the BRAF V600E mutation and have shown a remarkable response to vemurafenib. <b><i>Case Presentation:<\/i><\/b> We describe herein a patient with a history of stroke-like symptoms and retroperitoneal fibrosis that on initial pathology raised the possibility of IgG4-related disease. However, the patient was refractory to high-dose steroids and progressed further, developing an epicardial soft tissue mass and recurrent neurological symptoms. Integration of the above findings with new information at another hospital about a radiological history of symmetrical lower extremities long bone lesions raised the differential diagnosis of ECD. Molecular analysis of formalin-fixed paraffin-embedded tissue of both of the patient\u2019s retroperitoneal biopsies (the second one of which had shown a small focus of foamy histiocytes, CD68+\/CD1a\u2013) was positive for BRAF mutation, confirming the diagnosis of ECD. The patient demonstrated a dramatic and sustained metabolic response to vemurafenib on follow-up positron emission tomography scans. <b><i>Conclusion:<\/i><\/b> This case highlights the need for developing a high index of suspicion for presentations of retroperitoneal fibrosis that <i>could<\/i> represent IgG4-related disease but fail to respond to steroids. When unusual multisystem involvement occurs, one should consider a diagnosis of a rare histiocytosis. Vemurafenib appears to be an effective treatment for even advanced cases of both ECD and Langerhans histiocytosis bearing the BRAF V600E mutation.<\/jats:p>","DOI":"10.1159\/000477658","type":"journal-article","created":{"date-parts":[[2017,7,11]],"date-time":"2017-07-11T21:04:49Z","timestamp":1499807089000},"page":"613-619","source":"Crossref","is-referenced-by-count":9,"title":["Erdheim-Chester Disease: The Importance of Information Integration"],"prefix":"10.1159","volume":"10","author":[{"given":"Anna","family":"Nikonova","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Khashayar","family":"Esfahani","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Guillaume","family":"Chausse","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Stephan","family":"Probst","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Tina","family":"Petrogiannis-Haliotis","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hans","family":"Knecht","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Genevieve","family":"Gyger","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"127","published-online":{"date-parts":[[2017,7,11]]},"reference":[{"key":"ref1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ejim.2015.03.004"},{"key":"ref2","doi-asserted-by":"publisher","DOI":"10.1016\/j.mayocp.2015.03.020"},{"key":"ref3","doi-asserted-by":"publisher","DOI":"10.1038\/modpathol.2012.72"},{"key":"ref4","doi-asserted-by":"publisher","DOI":"10.1097\/BOR.0b013e328341a240"},{"key":"ref5","doi-asserted-by":"publisher","DOI":"10.1002\/art.27435"},{"key":"ref6","doi-asserted-by":"publisher","DOI":"10.1182\/blood-2010-06-294108"},{"key":"ref7","doi-asserted-by":"publisher","DOI":"10.1097\/01.md.0000145368.17934.9"},{"key":"ref8","doi-asserted-by":"publisher","DOI":"10.1200\/JCO.2014.57.1950"},{"key":"ref9","doi-asserted-by":"publisher","DOI":"10.1212\/WNL.0000000000000979"},{"key":"ref10","doi-asserted-by":"publisher","DOI":"10.1177\/0194599814533648"},{"key":"ref11","doi-asserted-by":"publisher","DOI":"10.2500\/ar.2012.3.0026"},{"key":"ref12","doi-asserted-by":"publisher","DOI":"10.1007\/s11102-013-0498-9"}],"container-title":["Case Reports in Oncology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.karger.com\/Article\/Pdf\/477658","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.karger.com\/Article\/Pdf\/477658","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.karger.com\/Article\/Pdf\/477658","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,4,23]],"date-time":"2025-04-23T16:32:23Z","timestamp":1745425943000},"score":1,"resource":{"primary":{"URL":"https:\/\/karger.com\/article\/doi\/10.1159\/000477658"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2017,7,11]]},"references-count":12,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2017,9,5]]}},"URL":"https:\/\/doi.org\/10.1159\/000477658","archive":["Portico"],"relation":{},"ISSN":["1662-6575"],"issn-type":[{"value":"1662-6575","type":"electronic"}],"subject":[],"published":{"date-parts":[[2017,7,11]]}}}