title: MR imaging of histiocytic sarcoma of the canine brain.
abstract: Histiocytic sarcomas are characterized by proliferation and/or infiltration of neoplastic histiocytes localized to specific organs, unlike malignant histiocytosis which involves many organ systems. Only a few cranial histiocytic sarcomas have been reported. Here we describe four dogs that presented with neurological deficits referable to the forebrain, and were diagnosed histologically as having histiocytic sarcoma. Using magnetic resonance (MR) imaging, the tumors were characterized by a T2-hyperintense and T1-isointense mass in one dog, T2- and T1-isointense extraaxial masses in two dogs, and a diffuse T2-hyperintense lesion over the left cerebral cortex in one dog. All tumors had contrast enhancement. MRI features in three of the four dogs were similar to that of meningioma, supported by the observation of a dural tail in two of these three dogs, and a broad base of attachment in the other. In the other dog the imaging findings were similar to those of encephalitis. Intracranial histiocytic sarcoma does not appear to have specific MR imaging features and can be confused with meningioma or encephalitis.
authors.affiliation: Tamura Animal Clinic, 7-16, Yoshimien, Saeki-ku, Hiroshima 731-5132, Japan. cqx03426@m58.megaegg.ne.jp
authors.forename: Shinji
authors.initials: S
authors.lastname: Tamura
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Tamura
authors.forename: Yuya
authors.initials: Y
authors.lastname: Nakamoto
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Ozawa
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Uchida
mesh_terms: D000818:Animals; D001921:Brain / Q000473:pathology; D001932:Brain Neoplasms / Q000175:diagnosis / Q000662:veterinary*; D003287:Contrast Media / Q000008:administration & dosage; D003937:Diagnosis, Differential; D004283:Dog Diseases / Q000175:diagnosis*; D004285:Dogs; D005260:Female; D054747:Histiocytic Sarcoma / Q000175:diagnosis / Q000662:veterinary*; D008279:Magnetic Resonance Imaging / Q000379:methods / Q000662:veterinary*; D008297:Male; D012189:Retrospective Studies
chemical_list: D003287:Contrast Media