Small Animal Radiology and Ultrasound: A Diagnostic Atlas and Text

86 Small Animal Radiolo g y and Ultrasono graphy
Fig. 2-60 A and B, A 2-year-old male mixed breed dog with a
history of having been kicked by a horse 2 weeks previously. Softtissue
swelling was present on the right thoracic wall. The dog had
evidence of mild respiratory distress. There is a soft-tissue density
in the right hemithorax. The cardiac silhouette and trachea are
displaced to the left. The diaphragmatic outline is obliterated.
There is bony proliferation on the cortical margins of the eighth
and ninth ribs. There is destruction involving the ventral aspect
of the eighth rib at the costochondral junction (arrows). There is
irregular soft-tissue mineralization noted in this area. The radiographic
changes are indicative of a pleural mass that has displaced
the cardiac silhouette. Although other causes of pleural
fluid and mass should also be considered in a differential diagnosis,
the bony lesion indicates that the mass is extrapleural and
arising from the ribs. Diagnosis: Fibrosarcoma.
A
B