Achados radiográficos, citopatológicos e/ou histopatológicos de tumores ósseos de cães atendidos no Hospital Veterinário da Universidade Federal de Uberlândia

Abstract

Osteosarcoma is the most common primary bone tumor in dogs, and must be differentiated from less common malignant primary bone tumors; in addition to osteomyelitis. The diagnosis can be made through radiographic examination of the affected bone; however, these bone disorders have very similar findings, requiring a histopathological and/or cytopathological differential diagnosis. The aim of this study was to survey the radiographic, histopathological and cytopathological findings of bone lesions in patients treated at the Veterinary Hospital of the Federal University of Uberlândia (HOVET-UFU). The dogs included were of random breed, sex, age and weight, and were treated by the Animal Pathology Sector HOVET-UFU, from January 2017 to December 2021, diagnosed through histopathological and/or cytopathological examination as a neoplastic process or inflammatory bone. Epidemiological data, bone tumor location, descriptions of lesions on radiography, histopathology and/or cytopathology were collected. Age and weight data were expressed as the mean ± S.E.M (standard error of the mean). To relate the epidemiological variables age, sex, race, weight and location (affected bone) and the diagnosis of osteosarcoma through cytopathological and/or histopathological examinations, the chi-square test or Fisher's exact test was used, considering significant the results of p < 0.05. 36 cases were found and of these 23 radiographic exams. The diagnosis of osteosarcoma was attributed to 23 lesions (23/36 - 63.8%), three cases were inflammatory lesions (3/36 - 8.3%), two dogs had fibrous osteodystrophy (2/36 - 5.5% ), one dog osteoma (1/36 - 2.7%), one dog had primary bone fibrosarcoma (1/36 - 2.7%), one case had bone callus (1/36 - 2.7%) and one case of osteopetrosis (1/36 - 2.7%), and four cases had an inconclusive diagnosis (4/36 - 11.1%). Fisher's exact test showed an association between sex and osteosarcoma, being more frequent in females, but there was no relationship between race, age and weight with osteosarcoma. Osteosarcoma represented 92% (23/25) of primary bone neoplasms, the most frequent histopathological type being fibroblastic (31.25% - 5/16). Twenty-three radiographic exams were found, and of these, 17 were of primary bone tumors and 2 of inflammatory lesions. Of the tumors, 82.3% (14/17) were aggressive bone lesions. Osteolysis was classified in 82.3% (14/17) of the exams as permeative, 35.2% (6/17) of the periosteal reactions were spiculated, 76.4% (13/17) had an indistinct transition zone, and 64.7% (11/17) of the tumors were monostotic. The atomic bomb-shaped periosteum reaction was present in 11.7% (2/17) of the cases. Codman's triangle was visualized in 11.7% of cases (2/17). As for the pattern, mixed was the most common, with 52.9% (9/17). The information was important to say about the adequate collection of samples for the cytopathological and histopathological exams. Furthermore, discussions arise about the importance of studying primary bone neoplasms and bone infections, for better interpretations of diagnostic tests.