{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T14:09:13Z","timestamp":1785420553533,"version":"3.56.0"},"reference-count":11,"publisher":"BMJ","issue":"7","content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Case Rep"],"accepted":{"date-parts":[[2026,7,21]]},"published-print":{"date-parts":[[2026,7]]},"abstract":"<jats:p>\n                    Secondary iliopsoas abscess arising from colorectal cancer is uncommon and diagnostically challenging. We report a woman in her 50s with locally recurrent sigmoid colon cancer who developed a massive gas-forming left iliopsoas abscess during capecitabine, oxaliplatin and bevacizumab. The acute presentation was severe, with altered consciousness reported before ambulance transfer, marked inflammatory response and need for urgent CT-guided drainage and intensive monitoring. Previous\n                    <jats:italic>Escherichia coli<\/jats:italic>\n                    bacteraemia, bilateral ureteral stents, polymicrobial anaerobic abscess flora and bevacizumab exposure created several plausible infection mechanisms. Abscess culture supported an enteric source whereas urine culture yielded discordant organisms. She improved after source control, broad-spectrum antimicrobial therapy with subsequent de-escalation and prolonged drainage, and was discharged after resuming systemic therapy without bevacizumab. This case emphasises early CT, multidisciplinary decision-making and cautious attribution of causality in oncology patients with flank pain and systemic inflammation.\n                  <\/jats:p>","DOI":"10.1136\/bcr-2026-275685","type":"journal-article","created":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T13:25:14Z","timestamp":1785417914000},"page":"e275685","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":0,"title":["Massive gas-forming iliopsoas abscess during bevacizumab-containing chemotherapy for recurrent sigmoid colon cancer: a diagnostic challenge"],"prefix":"10.1136","volume":"19","author":[{"given":"Naoki","family":"Nakagawa","sequence":"first","affiliation":[{"name":"Kawasaki Medical School Hospital, Kurashiki, Okayama, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Makoto","family":"Okawaki","sequence":"additional","affiliation":[{"name":"Clinical Oncology, Kawasaki Medical School Hospital, Kurashiki, Okayama, Japan"},{"name":"Advanced Oncology, Kawasaki Medical School, Kurashiki, Okayama, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Masatoshi","family":"Hirosaki","sequence":"additional","affiliation":[{"name":"Kawasaki Medical School Hospital, Kurashiki, Okayama, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4236-350X","authenticated-orcid":false,"given":"Takeshi","family":"Nagasaka","sequence":"additional","affiliation":[{"name":"Clinical Oncology, Kawasaki Medical School Hospital, Kurashiki, Okayama, Japan"},{"name":"Advanced Oncology, Kawasaki Medical School, Kurashiki, Okayama, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"239","published-online":{"date-parts":[[2026,7,30]]},"reference":[{"key":"2026073006250696000_19.7.e275685.1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ijsu.2012.08.016"},{"key":"2026073006250696000_19.7.e275685.2","doi-asserted-by":"crossref","first-page":"390","DOI":"10.1007\/BF02553381","article-title":"Psoas abscess resulting from perforating carcinoma of the sigmoid colon. Report of a case","volume":"26","author":"Peterson","year":"1983","journal-title":"Dis Colon Rectum"},{"key":"2026073006250696000_19.7.e275685.3","doi-asserted-by":"crossref","DOI":"10.1186\/1477-7819-7-74","article-title":"Retroperitoneal abscess complicated with necrotizing fasciitis of the thigh in a patient with sigmoid colon cancer","volume":"7","author":"Takakura","year":"2009","journal-title":"World J Surg Oncol"},{"key":"2026073006250696000_19.7.e275685.4","doi-asserted-by":"crossref","first-page":"342","DOI":"10.4055\/cios.2011.3.4.342","article-title":"Psoas abscess caused by spontaneous rupture of colon cancer","volume":"3","author":"Yang","year":"2011","journal-title":"Clin Orthop Surg"},{"key":"2026073006250696000_19.7.e275685.5","doi-asserted-by":"crossref","unstructured":"Cacurri A , Cannata G , Trastulli S , et al . A rare case of perforated descending colon cancer complicated with a fistula and abscess of left iliopsoas and ipsilateral obturator muscle. Case Rep Surg 2014;2014. doi:10.1155\/2014\/128506","DOI":"10.1155\/2014\/128506"},{"key":"2026073006250696000_19.7.e275685.6","doi-asserted-by":"crossref","first-page":"1198592","DOI":"10.3389\/fonc.2023.1198592","article-title":"Retroperitoneal abscess as a presentation of colon cancer: The largest case set analysis to date, which extracted from our unit and the literature","volume":"13","author":"Zhou","year":"2023","journal-title":"Front Oncol"},{"key":"2026073006250696000_19.7.e275685.7","doi-asserted-by":"crossref","DOI":"10.1016\/j.ijscr.2024.109449","article-title":"A large iliopsoas abscess due to colon cancer complicated by bowel obstruction: A case report","volume":"117","author":"Nohmi","year":"2024","journal-title":"Int J Surg Case Rep"},{"key":"2026073006250696000_19.7.e275685.8","doi-asserted-by":"publisher","DOI":"10.1016\/S1470-2045(09)70112-3"},{"key":"2026073006250696000_19.7.e275685.9","doi-asserted-by":"publisher","DOI":"10.1097\/SAP.0b013e3181828141"},{"key":"2026073006250696000_19.7.e275685.10","doi-asserted-by":"publisher","DOI":"10.1016\/j.ejca.2012.02.052"},{"key":"2026073006250696000_19.7.e275685.11","article-title":"Gastrointestinal perforation associated with bevacizumab in metastatic colorectal cancer","volume":"7","author":"Fang","year":"2024","journal-title":"Cancer Rep"}],"container-title":["BMJ Case Reports"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1136\/bcr-2026-275685","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T13:25:15Z","timestamp":1785417915000},"score":1,"resource":{"primary":{"URL":"https:\/\/casereports.bmj.com\/lookup\/doi\/10.1136\/bcr-2026-275685"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,7]]},"references-count":11,"journal-issue":{"issue":"7","published-online":{"date-parts":[[2026,7,30]]},"published-print":{"date-parts":[[2026,7]]}},"alternative-id":["10.1136\/bcr-2026-275685"],"URL":"https:\/\/doi.org\/10.1136\/bcr-2026-275685","relation":{},"ISSN":["1757-790X"],"issn-type":[{"value":"1757-790X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,7]]}}}