{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,8,27]],"date-time":"2025-08-27T07:40:03Z","timestamp":1756280403964,"version":"3.44.0"},"reference-count":9,"publisher":"BMJ","issue":"5","content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Case Rep"],"accepted":{"date-parts":[[2021,4,22]]},"published-print":{"date-parts":[[2021,5]]},"abstract":"<jats:p>Gastrointestinal stromal tumours (GISTs) are the most common mesenchymal neoplasms of the gastrointestinal tract. Dedifferentiation in these tumours occurs rarely, and when it does occurs most commonly after prolonged treatment with imatinib. We report the case of a 64-year-old man who presented with a mass of 8\u00d77\u00d73 cm dimensions involving the duodenum and head of the pancreas. On histopathology, areas of anaplastic tumour cells were negative for DOG-1, c-kit, CD-34, desmin and panCK along with a molecular level study showing wild-type KIT and PDGFRA (platelet-derived growth factor receptor alpha) gene. Based on focal GIST-like areas and CD117 positivity and absence of prior therapy, the diagnosis of a de novo dedifferentiated GIST was made. These tumours need to be reported as they pose a diagnostic challenge and their predicted response rated to targeted molecular therapies are unclear as compared with their c-kit positive counterparts.<\/jats:p>","DOI":"10.1136\/bcr-2020-241442","type":"journal-article","created":{"date-parts":[[2021,5,7]],"date-time":"2021-05-07T11:57:07Z","timestamp":1620388627000},"page":"e241442","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":2,"title":["Rare case of a duodenal de novo dedifferentiated gastrointestinal stromal tumour"],"prefix":"10.1136","volume":"14","author":[{"given":"Pritik A","family":"Shah","sequence":"first","affiliation":[{"name":"Department of Hepato Pancreato Biliary (HPB) Surgery and Liver Transplant, HealthCare Global Enterprises Ltd, Bangalore, Karnataka, India"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Raghavendra","family":"Babu","sequence":"additional","affiliation":[{"name":"Department of Hepato Pancreato Biliary (HPB) Surgery and Liver Transplant, HealthCare Global Enterprises Ltd, Bangalore, Karnataka, India"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sowmya B","family":"Uthaiah","sequence":"additional","affiliation":[{"name":"Department of Histopathology, HealthCare Global Enterprises Ltd, Bangalore, Karnataka, India"},{"name":"Department of Histopathology, Strand Life Sciences, Bangalore, Karnataka, India"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Shekar","family":"Patil","sequence":"additional","affiliation":[{"name":"Department of Medical Oncology, HealthCare Global Enterprises Ltd, Bangalore, Karnataka, India"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"239","published-online":{"date-parts":[[2021,5,7]]},"reference":[{"key":"2025082700222824000_14.5.e241442.1","doi-asserted-by":"publisher","DOI":"10.1097\/00000478-199904000-00002"},{"key":"2025082700222824000_14.5.e241442.2","doi-asserted-by":"crossref","DOI":"10.3390\/cancers11050679","article-title":"Clinical diagnosis of gastrointestinal stromal tumor (GIST): from the molecular genetic point of view","volume":"11","author":"Wu","year":"2019","journal-title":"Cancers"},{"key":"2025082700222824000_14.5.e241442.3","doi-asserted-by":"publisher","DOI":"10.1007\/BF00349507"},{"key":"2025082700222824000_14.5.e241442.4","doi-asserted-by":"publisher","DOI":"10.1111\/j.1365-2559.2005.02179.x"},{"key":"2025082700222824000_14.5.e241442.5","doi-asserted-by":"crossref","first-page":"118","DOI":"10.1016\/j.anndiagpath.2018.12.005","article-title":"Dedifferentiated gastrointestinal stromal tumor: recent advances","volume":"39","author":"Karakas","year":"2019","journal-title":"Ann Diagn Pathol"},{"key":"2025082700222824000_14.5.e241442.6","doi-asserted-by":"crossref","DOI":"10.1186\/s12885-019-6085-3","article-title":"Case report of rhabdomyosarcomatous transformation of a primary gastrointestinal stromal tumor (GIST)","volume":"19","author":"Li","year":"2019","journal-title":"BMC Cancer"},{"key":"2025082700222824000_14.5.e241442.7","doi-asserted-by":"crossref","first-page":"264","DOI":"10.1016\/j.prp.2013.12.008","article-title":"Dedifferentiated gastrointestinal stromal tumor arising de novo from the small intestine","volume":"210","author":"Choi","year":"2014","journal-title":"Pathol Res Pract"},{"key":"2025082700222824000_14.5.e241442.8","doi-asserted-by":"publisher","DOI":"10.1097\/PAS.0b013e31826c1761"},{"key":"2025082700222824000_14.5.e241442.9","doi-asserted-by":"crossref","first-page":"479","DOI":"10.1111\/pin.12095","article-title":"Gastrointestinal stromal tumor with dedifferentiation to undifferentiated pleomorphic sarcoma","volume":"63","author":"Jung","year":"2013","journal-title":"Pathol Int"}],"container-title":["BMJ Case Reports"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1136\/bcr-2020-241442","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,8,27]],"date-time":"2025-08-27T07:22:40Z","timestamp":1756279360000},"score":1,"resource":{"primary":{"URL":"https:\/\/casereports.bmj.com\/lookup\/doi\/10.1136\/bcr-2020-241442"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,5]]},"references-count":9,"journal-issue":{"issue":"5","published-online":{"date-parts":[[2021,5,7]]},"published-print":{"date-parts":[[2021,5]]}},"alternative-id":["10.1136\/bcr-2020-241442"],"URL":"https:\/\/doi.org\/10.1136\/bcr-2020-241442","relation":{},"ISSN":["1757-790X"],"issn-type":[{"type":"electronic","value":"1757-790X"}],"subject":[],"published":{"date-parts":[[2021,5]]}}}