Histiocytic Sarcoma in the Brain of a Cat

Abstract

ABSTRACT. A mass lesion in the subependymal region of the lateral ventricle in a 13-year-old neutered male mongrel cat with a complaint of somnolence, right circling movement and posture abnormality was examined. The magnetic resonance image examination revealed a relatively large T1-hypointense and T2-hyperintense mass lesion 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 brain lesion 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 alphachain and ionized calcium binding adaptor molecule 1, and few were positive for lysozyme and alpha-1 antichymotrypsin. 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 histiocytic sarcoma.KEY WORDS: brain, feline, histiocytic sarcoma, immunohistochemistry.J. Vet. Med. Sci. 72(1): 99-102, 2010 In dogs, histiocytic disorders have been classified into 3 major categories: canine cutaneous histiocytoma; canine reactive histiocytoses (both cutaneous and systemic); and histiocytic sarcoma complex (both localized and disseminated histiocytic sarcoma) [10]. Cats, in contrast, are rarely affected by these diseases [6]. Histiocytic sarcoma (HS) in cats has been reported to date in the intestinal wall, femur, tarsus, spleen and liver, and mediastinal and vertebral canals [1,5,11,13,16]. A brief description of an HS in the central nervous system (CNS) of a cat was reported only in a review article [19], while malignant histiocytic disorders have been well demonstrated in the canine CNS [2,4,14,18,20]. This report documents the features of a brain tumor in a cat. The histological and immunohistochemical natures characterized by the proliferation of highly pleomorphic cells resembling histiocytes and immunoreactivity for HLA-DR and ionized calcium binding adaptor molecule 1 (Iba1) are consistent with HS [7,8,15].A 13-year-old neutered male mongrel cat was presented to a private animal hospital with a complaint of somnolence, blindness, right circling movement and posture abnormality. The neurological examinations revealed a postural reaction decrease, a left mydriasis and disappearance of a physiologic nystagmus. Complete blood cell count and serum biochemical analyses were within normal ranges...

Diagnostic Immunohistochemistry of Canine and Feline Intracalvarial Tumors in the Age of Brain Biopsies

“…Most cases have been described in dogs, but at least 1 feline case had similar morphologic characteristics and was confirmed by positive a-1-chymotrypsin labeling. 50 Like all sarcomas, histiocytic sarcomas are vimentin positive, but tumor cells should be negative for S100, glial fibrillary acidic protein (GFAP), cytokeratin, neurofilament proteins, and lymphocytic markers. 146 Histiocytic sarcomas comprised 8 of 177 neoplasms in the brains of dogs and were approximately half as common as lymphomas.…”

Presumptive histiocytic neoplasm with unusual immunophenotype in a cat

“…Despite the fact that occasional cats have been FeLV and/or FIV positive, as was also true for this cat (Kraje et al 2001;Ide et al 2010), the vast majority of the reported cats have tested negative, challenging any association between HS and the retroviruses (Moore and Ogilvie 2001).…”

“…These cells demonstrated moderate anicocytosis and anisokaryosis, had a centrally or eccentrically located round-to-oval large nucleus or were occasionally binucleate, with coarse chromatic pattern and one or two distinct nucleoli; cytoplasm was moderately basophilic with numerous punctuate vacuoles. Giemsa, ×100 objective (Tanimoto et al 1988;Gafner and Bestetti 1988;Court et al 1993;Freeman et al 1995;Fritz et al 1999;Walton et al 1997;Vernau et al 2001;Kraje et al 2001;Austin and Henderson 2003;Smoliga et al 2005;Pinard et al 2006;Reed et al 2006;Weiss 2006;Bell et al 2006;Cortese et al 2008;Friedrichs and Young 2008;Ide et al 2009Ide et al , 2010. Pulmonary Langerhans cell histiocytosis, was recently recognized post-mortem in four cats (Busch et al 2008;Moore and Affolter 2010).…”

“…However, CBC may be unremarkable on admission, especially when HS affects the central nervous system or skeleton (Austin and Henderson 2003;Smoliga et al 2005;Pinard et al 2006;Ide et al 2010). Myelophthisis, immune-mediated hemolysis (Coombs , and/or autoagglutination positive cats), direct non immune-mediated erythrophagocytosis and the anemia of chronic disease, singly or in combination, are thought to largely account for the anemia in feline HS (Kraje et al 2001).…”

Lymphangiomatosis of the Systemic Skin in an Old Dog

“…2C). Atypical features such as endothelial tufting, nuclear atypia, and mitotic [12,13]. Both the endothelial cells and the spindle-shaped cells were positive for factor VIII-related antigen (Fig.…”