{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,16]],"date-time":"2026-07-16T05:04:37Z","timestamp":1784178277046,"version":"3.55.0"},"reference-count":20,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2026,7,13]],"date-time":"2026-07-13T00:00:00Z","timestamp":1783900800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Veterinary Sciences"],"abstract":"<jats:p>Synchronous low-grade alimentary lymphoma and gastrointestinal mast cell tumor have recently been described in cats. This report describes synchronous low-grade alimentary lymphoma and gastrointestinal mast cell tumor involving the jejunum in a cat. A 2.3 kg, 15-year-old, spayed female Chinchilla Persian cat presented with vomiting, diarrhea, anorexia, and lethargy. Ultrasonography and computed tomography demonstrated diffuse intestinal wall thickening and a focal jejunal lesion characterized by marked transmural thickening with loss of wall layering. Exploratory laparotomy and full-thickness intestinal biopsies were conducted. Histopathologic and immunohistochemical examination revealed two morphologically distinct neoplastic populations involving different jejunal wall layers. The two populations were anatomically adjacent but remained distinct without convincing intermingling in the examined histologic sections. These findings supported the interpretation of a lesion most consistent with a collision pattern. The affected intestinal segment was surgically resected, and chlorambucil and prednisolone were administered postoperatively. Clinical signs resolved, imaging abnormalities improved, and no evidence of local gastrointestinal mast cell tumor recurrence or progression of low-grade alimentary lymphoma was detected during the 14-month follow-up period. This case expands the currently recognized morphologic spectrum of synchronous feline intestinal neoplasia and highlights the importance of comprehensive histopathologic assessment and full-thickness intestinal biopsies for accurate diagnosis.<\/jats:p>","DOI":"10.3390\/vetsci13070681","type":"journal-article","created":{"date-parts":[[2026,7,14]],"date-time":"2026-07-14T02:34:44Z","timestamp":1783996484000},"page":"681","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Synchronous Low-Grade Alimentary Lymphoma and Gastrointestinal Mast Cell Tumor with a Collision Pattern in a Cat"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-0715-0429","authenticated-orcid":false,"given":"Jihee","family":"Han","sequence":"first","affiliation":[{"name":"Department of Veterinary Internal Medicine, College of Veterinary Medicine, Chungnam University, Daejeon 34134, Republic of Korea"},{"name":"Time Animal Medical Center, Daejeon 35233, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sijin","family":"Cha","sequence":"additional","affiliation":[{"name":"Time Animal Medical Center, Daejeon 35233, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jeonghyun","family":"Seo","sequence":"additional","affiliation":[{"name":"Time Animal Medical Center, Daejeon 35233, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8478-2035","authenticated-orcid":false,"given":"Kunho","family":"Song","sequence":"additional","affiliation":[{"name":"Department of Veterinary Internal Medicine, College of Veterinary Medicine, Chungnam University, Daejeon 34134, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,7,13]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"28","DOI":"10.5326\/JAAHA-MS-5554","article-title":"Recent trends in feline intestinal neoplasia: An epidemiologic study of 1,129 cases in the veterinary medical database from 1964 to 2004","volume":"47","author":"Rissetto","year":"2011","journal-title":"J. Am. Anim. Hosp. Assoc."},{"key":"ref_2","unstructured":"Vail, D.M., Thamm, D.H., and Liptak, J.M. (2020). Feline lymphoma and leukemia. Withrow and MacEwen\u2019s Small Animal Clinical Oncology, Elsevier. [6th ed.]."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Paulin, M.V., Couronn\u00e9, L., Beguin, J., Le Poder, S., Delverdier, M., Semin, M.O., Bruneau, J., Cerf-Brensussan, N., Malamut, G., and Cellier, C. (2018). Feline low-grade alimentary lymphoma: An emerging entity and a potential animal model for human disease. BMC Vet. Res., 14.","DOI":"10.1186\/s12917-018-1635-5"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"191","DOI":"10.1177\/1098612X12439266","article-title":"Feline alimentary lymphoma. 2. Further diagnostics, therapy and prognosis","volume":"14","author":"Barrs","year":"2012","journal-title":"J. Feline Med. Surg."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"51","DOI":"10.1002\/vms3.9","article-title":"Outcome and toxicity assessment of feline small cell lymphoma: 56 cases (2000\u20132010)","volume":"1","author":"Pope","year":"2015","journal-title":"Vet. Med. Sci."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"413","DOI":"10.5326\/0460413","article-title":"Treatment of feline gastrointestinal small-cell lymphoma with chlorambucil and glucocorticoids","volume":"46","author":"Stein","year":"2010","journal-title":"J. Am. Anim. Hosp. Assoc."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"280","DOI":"10.1177\/1098612X15581205","article-title":"Feline intestinal mast cell tumours: Clinicopathological characterisation and KIT mutation analysis","volume":"18","author":"Sabattini","year":"2016","journal-title":"J. Feline Med. Surg."},{"key":"ref_8","unstructured":"Vail, D.M., Thamm, D.H., and Liptak, J.M. (2020). Mast cell tumors. Withrow and MacEwen\u2019s Small Animal Clinical Oncology, Elsevier. [6th ed.]."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"188","DOI":"10.1111\/vco.12326","article-title":"Outcome following treatment of feline gastrointestinal mast cell tumours","volume":"16","author":"Barrett","year":"2018","journal-title":"Vet. Comp. Oncol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1098612X251341769","DOI":"10.1177\/1098612X251341769","article-title":"Standardized classification of synchronous gastrointestinal small cell lymphoma and gastrointestinal mast cell tumors in 15 cats","volume":"27","author":"Hohenhaus","year":"2025","journal-title":"J. Feline Med. Surg."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"941","DOI":"10.2460\/javma.251.8.941","article-title":"Malignant collision tumors in two dogs","volume":"251","author":"Scott","year":"2017","journal-title":"J. Am. Vet. Med. Assoc."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"330","DOI":"10.1111\/j.1740-8261.2010.01792.x","article-title":"Ultrasonography of intestinal mast cell tumors in the cat","volume":"52","author":"Laurenson","year":"2011","journal-title":"Vet. Radiol. Ultrasound"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"e14236","DOI":"10.1111\/dth.14236","article-title":"Collision tumors: A review of their types, pathogenesis, and diagnostic challenges","volume":"33","author":"Bulte","year":"2020","journal-title":"Dermatol. Ther."},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Ribatti, D., and D\u2019Amati, A. (2023). Hematopoiesis and mast cell development. Int. J. Mol. Sci., 24.","DOI":"10.3390\/ijms241310679"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"8","DOI":"10.1038\/s41420-024-02258-y","article-title":"Mast cells: Key players in digestive system tumors and their interactions with immune cells","volume":"11","author":"Shu","year":"2025","journal-title":"Cell Death Discov."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"2042","DOI":"10.1182\/blood-2012-03-415638","article-title":"Mast cells play a protumorigenic role in primary cutaneous lymphoma","volume":"120","author":"Rabenhorst","year":"2012","journal-title":"Blood"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1447","DOI":"10.2460\/javma.229.9.1447","article-title":"Comparison of endoscopic and full-thickness biopsy specimens for diagnosis of inflammatory bowel disease and alimentary tract lymphoma in cats","volume":"229","author":"Evans","year":"2006","journal-title":"J. Am. Vet. Med. Assoc."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"794","DOI":"10.1111\/jvim.16690","article-title":"ACVIM consensus statement guidelines on diagnosing and distinguishing low-grade neoplastic from inflammatory lymphocytic chronic enteropathies in cats","volume":"37","author":"Marsilio","year":"2023","journal-title":"J. Vet. Intern Med."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"e000172","DOI":"10.1136\/esmoopen-2017-000172","article-title":"Multiple primary tumours: Challenges and approaches, a review","volume":"2","author":"Vogt","year":"2017","journal-title":"ESMO Open"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"e28988","DOI":"10.1097\/MD.0000000000028988","article-title":"Synchronous or collision solid neoplasms and lymphomas: A systematic review of 308 case reports","volume":"101","author":"Rocha","year":"2022","journal-title":"Medicine"}],"container-title":["Veterinary Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2306-7381\/13\/7\/681\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,16]],"date-time":"2026-07-16T04:23:34Z","timestamp":1784175814000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2306-7381\/13\/7\/681"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,7,13]]},"references-count":20,"journal-issue":{"issue":"7","published-online":{"date-parts":[[2026,7]]}},"alternative-id":["vetsci13070681"],"URL":"https:\/\/doi.org\/10.3390\/vetsci13070681","relation":{},"ISSN":["2306-7381"],"issn-type":[{"value":"2306-7381","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,7,13]]}}}