{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,27]],"date-time":"2026-02-27T12:32:45Z","timestamp":1772195565002,"version":"3.50.1"},"reference-count":20,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2026,2,27]],"date-time":"2026-02-27T00:00:00Z","timestamp":1772150400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Minister of Science"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Animals"],"abstract":"<jats:p>Ectopic liver is a rare anomaly characterized by the presence of hepatic tissue outside its normal anatomical location without continuity with the main liver. Reports of this condition are sporadic in human medicine, and cases in veterinary species remain limited. This condition may arise as a congenital developmental defect or as a consequence of prior traumatic injury leading to fragmentation and displacement of hepatic tissue. This case study describes an incidental intrathoracic ectopic liver identified in a 6-year-old male cat that died of acute suppurative bacterial pneumonia. Necropsy revealed a well-demarcated, encapsulated, large mass within the middle of the caudal mediastinum, unattached to the diaphragm, lungs, or pericardium. Cytologic and histopathologic examinations confirmed the presence of hepatic tissue with preserved lobular architecture. No evidence of previous trauma or diaphragmatic defects was present, supporting the congenital origin. The accompanying severe bacterial pneumonia was unrelated to the mediastinal mass. This study highlights the diagnostic challenges associated with intrathoracic ectopic liver, which can mimic neoplastic or inflammatory masses. Awareness of this entity is essential for accurate diagnosis. Given the documented risk of malignant transformation in ectopic hepatic tissue, surgical excision and histopathological assessment should be considered whenever such lesions are detected.<\/jats:p>","DOI":"10.3390\/ani16050742","type":"journal-article","created":{"date-parts":[[2026,2,27]],"date-time":"2026-02-27T10:41:02Z","timestamp":1772188862000},"page":"742","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["An Incidental Necropsy Finding: Intrathoracic Ectopic Liver in a Cat"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-4857-9491","authenticated-orcid":false,"given":"Joanna","family":"Fiedorowicz","sequence":"first","affiliation":[{"name":"Department of Pathological Anatomy, Faculty of Veterinary Medicine, University of Warmia and Mazury in Olsztyn, Oczapowskiego 13, 10-719 Olsztyn, Poland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7661-7993","authenticated-orcid":false,"given":"Katarzyna","family":"Pa\u017adzior-Czapula","sequence":"additional","affiliation":[{"name":"Department of Pathological Anatomy, Faculty of Veterinary Medicine, University of Warmia and Mazury in Olsztyn, Oczapowskiego 13, 10-719 Olsztyn, Poland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3546-2032","authenticated-orcid":false,"given":"Mateusz","family":"Mikiewicz","sequence":"additional","affiliation":[{"name":"Department of Pathological Anatomy, Faculty of Veterinary Medicine, University of Warmia and Mazury in Olsztyn, Oczapowskiego 13, 10-719 Olsztyn, Poland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3271-0408","authenticated-orcid":false,"given":"Iwona","family":"Otrocka-Domaga\u0142a","sequence":"additional","affiliation":[{"name":"Department of Pathological Anatomy, Faculty of Veterinary Medicine, University of Warmia and Mazury in Olsztyn, Oczapowskiego 13, 10-719 Olsztyn, Poland"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2026,2,27]]},"reference":[{"key":"ref_1","first-page":"27","article-title":"Ectopic liver","volume":"67","author":"Collan","year":"1978","journal-title":"Ann. Chir. Gynaecol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"534","DOI":"10.4240\/wjgs.v12.i12.534","article-title":"Ectopic liver tissue (choristoma) on the gallbladder: A comprehensive literature review","volume":"12","author":"Akbulut","year":"2020","journal-title":"World J. Gastrointest. Surg."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"39","DOI":"10.5326\/0450039","article-title":"Ectopic hepatic parenchyma attached to the diaphragm: Simulating a pulmonary mass in a cat","volume":"45","author":"Dhaliwal","year":"2009","journal-title":"J. Am. Anim. Hosp. Assoc."},{"key":"ref_4","first-page":"215","article-title":"Intrapericardial hepatic choristoma in a cat","volume":"32","author":"Nogueira","year":"2010","journal-title":"Rev. Bras. Med. Vet."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"711","DOI":"10.1292\/jvms.13-0532","article-title":"Intrathoracic ectopic liver in a cow","volume":"76","author":"Hifumi","year":"2014","journal-title":"J. Vet. Med. Sci."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"64","DOI":"10.12935\/jvma.68.64","article-title":"Intrathoracic ectopic liver in a dog","volume":"68","author":"Hifumi","year":"2015","journal-title":"J. Jpn. Vet. Med. Assoc."},{"key":"ref_7","first-page":"95","article-title":"An intrathoracic ectopic liver with pleural effusion in a dog","volume":"65","author":"Iwaki","year":"2017","journal-title":"Jpn. J. Vet. Res."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"750","DOI":"10.1111\/vru.13422","article-title":"Radiographic and computed tomographic findings of intrathoracic ectopic liver in a dog","volume":"65","author":"Jeong","year":"2024","journal-title":"Vet. Radiol. Ultrasound"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"106","DOI":"10.1080\/00480169.1986.35312","article-title":"Pericardial ectopic liver in a cat","volume":"34","author":"Jones","year":"1986","journal-title":"N. Z. Vet. J."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"342","DOI":"10.5326\/JAAHA-MS-6229","article-title":"Ectopic intrathoracic hepatic tissue and accessory lung lobe aplasia in a dog","volume":"51","author":"Lande","year":"2015","journal-title":"J. Am. Anim. Hosp. Assoc."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"e70157","DOI":"10.1002\/vrc2.70157","article-title":"Incidental finding on postmortem examination of an epicardial ectopic liver in a cat with concurrent feline infectious peritonitis (Felis catus)","volume":"13","author":"Talbot","year":"2025","journal-title":"Vet. Rec. Case Rep."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"465","DOI":"10.1080\/00480169.2005.36594","article-title":"Ectopic hepatocellular carcinoma in a dog","volume":"53","author":"Burton","year":"2005","journal-title":"N. Z. Vet. J."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"727","DOI":"10.1097\/01.meg.0000131037.92864.df","article-title":"Ectopic liver and hepatocarcinogenesis","volume":"16","author":"Caygill","year":"2004","journal-title":"Eur. J. Gastroenterol. Hepatol."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"702","DOI":"10.1292\/jvms.25-0048","article-title":"A case of ectopic hepatocellular carcinoma around the common bile duct in a dog","volume":"87","author":"Saito","year":"2025","journal-title":"J. Vet. Med. Sci."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1085","DOI":"10.1007\/s00276-018-2046-9","article-title":"Accessory liver within the thoracic cavity","volume":"40","author":"Adin","year":"2018","journal-title":"Surg. Radiol. Anat."},{"key":"ref_16","first-page":"6626299","article-title":"The first case report of ectopic hepatic tissue in a guinea pig","volume":"2021","author":"Kimura","year":"2021","journal-title":"Case Rep. Vet. Med."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"995","DOI":"10.1016\/j.theriogenology.2015.05.039","article-title":"Ectopic liver and gallbladder in a cloned dog: Possible nonheritable anomaly","volume":"84","author":"Kim","year":"2015","journal-title":"Theriogenology"},{"key":"ref_18","first-page":"553","article-title":"Ectopic liver anomaly in umbilical region of newly born calves: Clinical, pathological, sonographical and surgical investigations","volume":"14","author":"Gomaa","year":"2015","journal-title":"Glob. Vet."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"28","DOI":"10.1111\/jsap.12161","article-title":"Cytological and histological correlation in diagnosing feline and canine mediastinal masses","volume":"55","author":"Pintore","year":"2014","journal-title":"J. Small Anim. Pract."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Repyak, K., Atiee, G., Cook, A., Bryan, L., and Gremillion, C. (2025). Thoracic radiographic findings in cats with feline infectious peritonitis. J. Feline Med. Surg., 27.","DOI":"10.1177\/1098612X241309823"}],"container-title":["Animals"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-2615\/16\/5\/742\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,2,27]],"date-time":"2026-02-27T11:04:55Z","timestamp":1772190295000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-2615\/16\/5\/742"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,2,27]]},"references-count":20,"journal-issue":{"issue":"5","published-online":{"date-parts":[[2026,3]]}},"alternative-id":["ani16050742"],"URL":"https:\/\/doi.org\/10.3390\/ani16050742","relation":{},"ISSN":["2076-2615"],"issn-type":[{"value":"2076-2615","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,2,27]]}}}