XXXX in the brain of a cat.

@entity66 @entity75 @entity2058 @entity2147 @entity8698 @entity460
A @entity66 in the subependymal region of the lateral ventricle in a 13-year-old neutered male mongrel cat with a complaint of @entity2147 , right circling movement and posture abnormality was examined. The magnetic resonance image examination revealed a relatively large T1-hypointense and T2-hyperintense @entity66 in the left interventricular foramen region, and there were no abnormalities in the chest and abdominal x-ray radiographic, funduscopic, and electric retinogram findings. The cat was died 43 days after the initial referral, and the post-mortem examinations revealed a poorly demarcated subependymal mass. Histologically, the @entity75 consisted of complex proliferation of highly pleomorphic cells resembling histiocytes with atypia and abundant mitotic figures. Moderate infiltrates of small reactive lymphocytes were admixed with the pleomorphic cell population. Gemistcytic astrocytes were also intermingled with the periphery of neoplastic foci. Immunohistochemically, most of the pleomorphic cells were positive for HLA-DR alpha-chain and ionized @entity460 binding adaptor molecule 1, and few were positive for lysozyme and @entity8698 . The atypical pleomorphic cells were negative for CD3, IgG (H and L), glial fibrillary acidic protein and neurofilament, suggesting monocytic/histiocytic-origin of the cells. The number of Ki-67-positive cell nuclei was extremely large, reflecting the high growth activity of these cells. Based on the findings, the lesion was considered as @entity2058 .
