{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,16]],"date-time":"2026-04-16T14:49:36Z","timestamp":1776350976559,"version":"3.51.2"},"reference-count":23,"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>Pheochromocytomas and paragangliomas (PPGLs) are rare neuroendocrine tumours that usually present with symptoms related to catecholamine excess. However, a small subset may secrete cytokines such as interleukin-6 (IL-6), leading to atypical systemic manifestations and delayed recognition of a paraneoplastic inflammatory syndrome. We report the case of a middle-aged woman with a previously diagnosed non-secreting cervical paraganglioma who developed fever of unknown origin (FUO), anaemia and liver dysfunction 5 years after the initial diagnosis. Extensive investigations excluded infectious, autoimmune and haematological causes. Markedly elevated IL-6 levels suggested a paraneoplastic inflammatory syndrome. Corticosteroid therapy induced transient clinical improvement, while definitive surgical resection resulted in complete resolution of fever, normalisation of inflammatory markers and recovery of haematological and hepatic abnormalities. Histopathology confirmed IL-6 expression within tumour cells. This case highlights the importance of considering cytokine-secreting paragangliomas in patients with unexplained systemic inflammation, even in the absence of catecholamine hypersecretion.<\/jats:p>","DOI":"10.1136\/bcr-2026-272208","type":"journal-article","created":{"date-parts":[[2026,4,16]],"date-time":"2026-04-16T13:55:18Z","timestamp":1776347718000},"page":"e272208","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":0,"title":["Interleukin-6-producing non-secreting cervical paraganglioma presenting with fever of unknown origin and systemic inflammatory response syndrome"],"prefix":"10.1136","volume":"19","author":[{"given":"Valentina","family":"Rusconi","sequence":"first","affiliation":[{"name":"Arterial Hypertension and Cardiovascular Endocrinology Laboratory; Division of Endocrinology, Diabetes and Metabolism, City of Health and Science University Hospital of Turin, Turin, Itay"},{"name":"Department of Medical Sciences, University of Turin, Turin, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Angelica","family":"Clivio","sequence":"additional","affiliation":[{"name":"Department of Medical Sciences, University of Turin, Turin, Italy"},{"name":"Division of Internal Medicine 5, City of Health and Science University Hospital of Turin, Turin, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Matteo","family":"Ferrante","sequence":"additional","affiliation":[{"name":"Department of Medical Sciences, University of Turin, Turin, Italy"},{"name":"Division of Internal Medicine 5, City of Health and Science University Hospital of Turin, Turin, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Elisa","family":"Febbraro","sequence":"additional","affiliation":[{"name":"Arterial Hypertension and Cardiovascular Endocrinology Laboratory; Division of Endocrinology, Diabetes and Metabolism, City of Health and Science University Hospital of Turin, Turin, Itay"},{"name":"Department of Medical Sciences, University of Turin, Turin, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Luisa","family":"Chasseur","sequence":"additional","affiliation":[{"name":"Division of Internal Medicine 5, City of Health and Science University Hospital of Turin, Turin, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Eleonora","family":"Duregon","sequence":"additional","affiliation":[{"name":"Department of Oncology, University of Turin, Orbassano, Turin, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Luca","family":"Scaglione","sequence":"additional","affiliation":[{"name":"Division of Internal Medicine 5, City of Health and Science University Hospital of Turin, Turin, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6930-7073","authenticated-orcid":false,"given":"Mirko","family":"Parasiliti-Caprino","sequence":"additional","affiliation":[{"name":"Arterial Hypertension and Cardiovascular Endocrinology Laboratory; Division of Endocrinology, Diabetes and Metabolism, City of Health and Science University Hospital of Turin, Turin, Itay"},{"name":"Department of Medical Sciences, University of Turin, Turin, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"239","published-online":{"date-parts":[[2026,4,16]]},"reference":[{"key":"2026041606551044000_19.4.e272208.1","doi-asserted-by":"crossref","unstructured":"Lenders JWM , Kerstens MN , Amar L , et al . Genetics, diagnosis, management and future directions of research of phaeochromocytoma and paraganglioma. J Hypertens 2020;1443\u201356. doi:10.1097\/HJH.0000000000002438","DOI":"10.1097\/HJH.0000000000002438"},{"key":"2026041606551044000_19.4.e272208.2","doi-asserted-by":"crossref","DOI":"10.3390\/biomedicines10081813","article-title":"Clinical and Pathological Tools for Predicting Recurrence and\/or Metastasis in Patients with Pheochromocytoma and Paraganglioma","volume":"10","author":"Bima","year":"2022","journal-title":"Biomedicines"},{"key":"2026041606551044000_19.4.e272208.3","doi-asserted-by":"publisher","DOI":"10.1007\/s12022-022-09704-6"},{"key":"2026041606551044000_19.4.e272208.4","doi-asserted-by":"crossref","first-page":"152","DOI":"10.3803\/EnM.2017.32.2.152","article-title":"Update on Modern Management of Pheochromocytoma and Paraganglioma","volume":"32","author":"Lenders","year":"2017","journal-title":"Endocrinol Metab (Seoul)"},{"key":"2026041606551044000_19.4.e272208.5","doi-asserted-by":"crossref","DOI":"10.3390\/cancers11050724","article-title":"Malignant Pheochromocytomas\/Paragangliomas and Ectopic Hormonal Secretion: A Case Series and Review of the Literature","volume":"11","author":"Angelousi","year":"2019","journal-title":"Cancers (Basel)"},{"key":"2026041606551044000_19.4.e272208.6","doi-asserted-by":"crossref","first-page":"743","DOI":"10.1507\/endocrj.EJ24-0459","article-title":"Pheochromocytoma associated with ectopic ACTH-producing tumor and hyper-interleukin-6emia: a case report with review of literature","volume":"72","author":"Nakahira","year":"2025","journal-title":"Endocr J"},{"key":"2026041606551044000_19.4.e272208.7","doi-asserted-by":"crossref","first-page":"2253","DOI":"10.1007\/s40618-021-01532-5","article-title":"Interleukin-6 producing pheochromocytoma\/paraganglioma: case series from a tertiary referral centre for pheochromocytomas and paragangliomas","volume":"44","author":"Meijs","year":"2021","journal-title":"J Endocrinol Invest"},{"key":"2026041606551044000_19.4.e272208.8","doi-asserted-by":"publisher","DOI":"10.1016\/j.beem.2011.10.008"},{"key":"2026041606551044000_19.4.e272208.9","first-page":"1605","article-title":"Interleukin-6-producing paraganglioma mimicking multicentric Castleman disease","volume":"61","author":"Oya","year":"2020","journal-title":"Rinsho Ketsueki"},{"key":"2026041606551044000_19.4.e272208.10","doi-asserted-by":"crossref","first-page":"2105","DOI":"10.2169\/internalmedicine.55.4655","article-title":"Systemic Inflammatory Syndrome Associated with a Case of Jugular Paraganglioma","volume":"55","author":"Sokabe","year":"2016","journal-title":"Intern Med"},{"key":"2026041606551044000_19.4.e272208.11","doi-asserted-by":"crossref","unstructured":"Wang C , Guan M , Zhang S , et al . Case Report: A 65-year-old man with paraganglioma accompanied by elevated interleukin-6 levels and KIF1B single gene mutation. Front Endocrinol 2023;14. doi:10.3389\/fendo.2023.1226468","DOI":"10.3389\/fendo.2023.1226468"},{"key":"2026041606551044000_19.4.e272208.12","doi-asserted-by":"publisher","DOI":"10.1159\/000075808"},{"key":"2026041606551044000_19.4.e272208.13","doi-asserted-by":"publisher","DOI":"10.1210\/jcem-73-4-877"},{"key":"2026041606551044000_19.4.e272208.14","doi-asserted-by":"publisher","DOI":"10.1007\/BF03345202"},{"key":"2026041606551044000_19.4.e272208.15","doi-asserted-by":"publisher","DOI":"10.1507\/endocrj.52.193"},{"key":"2026041606551044000_19.4.e272208.16","doi-asserted-by":"crossref","first-page":"1843","DOI":"10.1590\/S1807-59322011001000028","article-title":"Interleukin-6-producing pheochromocytoma presenting with fever of unknown origin","volume":"66","author":"Yarman","year":"2011","journal-title":"Clinics (Sao Paulo)"},{"key":"2026041606551044000_19.4.e272208.17","doi-asserted-by":"publisher","DOI":"10.1055\/s-0028-1103300"},{"key":"2026041606551044000_19.4.e272208.18","first-page":"1605","article-title":"Interleukin-6-producing paraganglioma mimicking multicentric Castleman disease","volume":"61","author":"Oya","year":"2020","journal-title":"The Japanese journal of clinical hematology"},{"key":"2026041606551044000_19.4.e272208.19","doi-asserted-by":"crossref","first-page":"435","DOI":"10.12701\/jyms.2022.00766","article-title":"Interleukin-6-producing paraganglioma as a rare cause of systemic inflammatory response syndrome: a case report","volume":"40","author":"Lee","year":"2023","journal-title":"J Yeungnam Med Sci"},{"key":"2026041606551044000_19.4.e272208.20","doi-asserted-by":"publisher","DOI":"10.1046\/j.1365-2265.2001.01082.x"},{"key":"2026041606551044000_19.4.e272208.21","doi-asserted-by":"publisher","DOI":"10.1002\/1097-0142(19940901)74:5<1634::AID-CNCR2820740524>3.0.CO;2-W"},{"key":"2026041606551044000_19.4.e272208.22","doi-asserted-by":"crossref","DOI":"10.1136\/bcr.03.2012.6122","article-title":"Fever of unknown origin: a rare retroperitoneal cause","volume":"2012","author":"Davies","year":"2012","journal-title":"BMJ Case Rep"},{"key":"2026041606551044000_19.4.e272208.23","doi-asserted-by":"crossref","DOI":"10.1016\/j.esmoop.2024.104088","article-title":"Anti-IL-6R Ab tocilizumab to treat paraneoplastic inflammatory syndrome of solid cancers","volume":"10","author":"Blay","year":"2025","journal-title":"ESMO Open"}],"container-title":["BMJ Case Reports"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1136\/bcr-2026-272208","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,4,16]],"date-time":"2026-04-16T13:55:22Z","timestamp":1776347722000},"score":1,"resource":{"primary":{"URL":"https:\/\/casereports.bmj.com\/lookup\/doi\/10.1136\/bcr-2026-272208"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,4]]},"references-count":23,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2026,4,16]]},"published-print":{"date-parts":[[2026,4]]}},"alternative-id":["10.1136\/bcr-2026-272208"],"URL":"https:\/\/doi.org\/10.1136\/bcr-2026-272208","relation":{},"ISSN":["1757-790X"],"issn-type":[{"value":"1757-790X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,4]]}}}