title: Histological and immunohistochemical studies on primary intracranial canine histiocytic sarcomas.
abstract: Histiocytic sarcoma is a progressive and fatal malignant neoplasm that mainly occurs in middle- to old-aged dogs. This study describes clinicopathological, histological and immunohistochemical characteristics of intracranial histiocytic sarcomas in 23 dogs. Magnetic resonance imaging and/or computed tomography of the brains revealed that the tumors mainly located in the cerebrum, particularly the frontal lobe. Seizure was a predominant clinical sign in most of the cases. Histologically, the tumor cells were morphologically classified into round/polygonal- and spindle-shaped cell types. There was a significant association between tumor cell types and hemophagocytic activity (P<0.05). However, there was no significant difference in other clinicopathological parameters and mitotic index between the 2 types. Immunohistochemically, tumor cells were strongly positive for HLA-DR, Iba-1 and CD204 in all the 23 cases, for iNOS in 20, for CD163 in 17, for CD208 (DC-LAMP) in 9, for lysozyme in 8 and for S100 in 5 cases. In addition, the Ki67-proliferative index showed range of 0.50-64.33% (Average 26.60 ± 3.81%). These observations suggest that canine primary intracranial histiocytic sarcomas tend to exhibit both dendritic cell and macrophage phenotypes of histiocytic differentiation.
authors.affiliation: Department of Veterinary Pathology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
authors.forename: Atigan
authors.initials: A
authors.lastname: Thongtharb
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Uchida
authors.forename: James Kenn
authors.initials: JK
authors.lastname: Chambers
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Kagawa
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Nakayama
mesh_terms: D000818:Animals; D014408:Biomarkers, Tumor / Q000378:metabolism; D001932:Brain Neoplasms / Q000473:pathology / Q000662:veterinary*; D004283:Dog Diseases / Q000473:pathology*; D004285:Dogs; D005260:Female; D054747:Histiocytic Sarcoma / Q000473:pathology / Q000662:veterinary*; D007150:Immunohistochemistry / Q000662:veterinary; D008297:Male
chemical_list: D014408:Biomarkers, Tumor