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The persistently rising CEA prompted a repeat colonoscopy, upper gastrointestinal and small bowel investigation and a CT of the abdomen and pelvis, without any cause being found. Finally, a CT-positron emission tomography scan revealed localised uptake in the thyroid gland, with a fine-needle aspiration confirming a diagnosis of medullary cell thyroid carcinoma with regional lymph node involvement.<\/jats:p>","DOI":"10.1136\/bcr-2025-270871","type":"journal-article","created":{"date-parts":[[2026,4,8]],"date-time":"2026-04-08T10:55:15Z","timestamp":1775645715000},"page":"e270871","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":0,"title":["Functional bowel disease symptoms and a de novo raised carcinoembryonic antigen: delayed diagnosis of medullary cell thyroid carcinoma"],"prefix":"10.1136","volume":"19","author":[{"given":"Lucy Alyssa","family":"Hebden","sequence":"first","affiliation":[{"name":"University Hospitals Bristol and Weston NHS Foundation Trust, Bristol, England, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Abuajela","family":"Sreh","sequence":"additional","affiliation":[{"name":"Doncaster and Bassetlaw Teaching Hospitals NHS Foundation Trust, Doncaster, England, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0002-2442-605X","authenticated-orcid":false,"given":"John Miles","family":"Hebden","sequence":"additional","affiliation":[{"name":"Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"239","published-online":{"date-parts":[[2026,4,8]]},"reference":[{"key":"2026062608154147000_19.4.e270871.1","doi-asserted-by":"publisher","DOI":"10.3393\/ac.2019.11.13"},{"key":"2026062608154147000_19.4.e270871.2","doi-asserted-by":"crossref","unstructured":"Sturgeon CM , Lai LC , Duffy MJ . 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