Primary bilateral renal diffuse large B-cell lymphoma with central nervous system metastases in a captive brown bear (Ursus arctos) - a case report.

• Main Authors: Beck, Ana, Reljić, Slaven, Šoštarić-Zuckermann, Ivan-Conrado, Wrzosek, Marcin, Huber, Doroteja
• Format: Review
• Language: English
• Published: Faculty of Veterinary Medicine University of Zagreb 2016
• Subjects: brown bear; Ursus arctos; primary renal large B-cell lymphoma; central nervous system metastases; pathology; smeđa medvjedica; primarni difuzni B-velikostanični limfom; bubreg; metastaze; središnji živčani sustav; patologija
• Online Access: http://hrcak.srce.hr/170235; http://hrcak.srce.hr/file/251082

We present the first report of primary bilateral renal diffuse large B-cell lymphoma with central nervous system metastases, in a 7 year-old, captive female brown bear. After 7 months of progressive neurological disease, the animal was euthanized. On necropsy, neoplastic nodules with infiltrative growth in the kidneys were found. Neoplastic proliferation of a similar pattern was found compressing the cerebellum and brain stem, and growing through the nervus maxillaris and nervus ophtalmicus. Histology revealed a highly cellular round cell neoplasm, with an infiltrative diffuse growth pattern through the kidneys and nervous parenchyma. On immunohistochemistry, the neoplastic cells stained for the B-cell marker Pax-5. Our report suggests that lymphoma should be considered as a differential diagnosis in bears with a chronic progressive neurological disease. Opisan je prvi slučaj bilateralnoga primarnog difuznog B-velikostaničnog limfoma bubrega s metastazama u tkivo središnjega živčanog sustava u sedmogodišnje smeđe medvjedice držane u zatočeništvu. Životinja je eutanizirana zbog sedmomjesečne progresivne neurološke bolesti. Obdukcija je pokazala postojanje nodularne infiltrativne neoplazme u oba bubrega. Također je utvrđeno neoplastično nodularno bujanje u području malog mozga i moždanog debla koje je dovelo do značajne kompresivne atrofije navedenih struktura te zahvatilo vidne i maksilarne živce. Histološka pretraga pokazala je da su bubrezi i mozak zahvaćeni difuznim infiltrativnim rastom neoplastičnih pojedinačnih okruglih stanica. Visoka imunohistokemijska pozitivnost neoplastičnih stanica na Pax-5 marker dokazala je da je riječ o B-staničnom limfomu. Ovaj nalaz trebao bi doprinijeti uvrštavanju limfoma na listu diferencijalnih dijagnoza u slučaju pojave kronične progresivne bolesti centralnog živčanog sustava u medvjeda.