Tumor ósseo multilobular em um cão / Multilobular tumor of bone in a dog

ABSTRACT

Background: Multilobular tumor of bone (MTB) is a primary bone neoplasm, uncommon in dogs. This tumor was called ofmany names for a long time, as chondroma rodens, multilobular osteochondrosarcoma, multilobular osteoma, multilobularchondroma, calcificating aponeurotic fibroma, although MTB was preferred chosen, because these other name could becorrelated with humans’ tumors. This tumor is observed specially in skull bone, although it was reported in zygomaticarc, hard palate, axilla, spine and penis. Mostly happen in big breeds dogs, and middle to old age patients. Clinical signsdepending of region and how aggressive the tumor is, usually are related to compression of any structure. The growth ofMTB is frequently slow and progressive, locally invasive, occurring relapse after surgical revomal, although the tumorhas low to moderate metastatic potential. The aim of this study is to report a case of MTB in a female dog and describeanatomopathological changes.Case A female dog, mixed breed, 13 year-old, of middleweight was admitted in Pathology Department of College of Agricultural Sciences and Veterinary Medicine (FCAV-Unesp), Campus of Jaboticabal - SP, to be undergone to necropsy. Thepatient have never shown any epileptic crisis or neurologic signs. In macroscopic examination was found a mass in skull,which invaded the orbit and frontal sinus, but it was not invading brain cavity. The neoplasm had and irregular surface, firmconsistent, color was white mixed to red areas, after cut it was granular and rough, and had some point mineralized areas.The lobs of lung had much firm masses, colored gray to white. In cytology it was observed fusiform to polyhedric isolatedmesenchymal cells, moderated pleomorphic, basophilic cytoplasm, thin granulated nuclear chromatin, and visible nucleolithat was involved by eosinophilic extracellular matrix...