Presentation
Presents with non weight-bearing lameness and firm swelling on the distal tibia of the right pelvic limb.
Patient Data
There is a large, expansile, destructive osseous lesion of the distal right tibia with cortical destruction most severe at the caudal and medial margins. There is also mild, irregular periosteal proliferation and soft tissue thickening at the site.
There are moderate diffuse bronchointerstitial pulmonary infiltrates. The cardiovascular structures appear within normal limits and there is no evidence of metastatic disease. Within the viewable abdomen, two mineral opacity pebbles are visualized within the stomach.
An oval soft tissue opacity is present superimposed over the aorta ventral to T7 on both lateral projections. This opacity is not observed on the DV projection and may be in either caudal lung lobe. The cardiovascular structures appear within normal limits.
Probable pulmonary metastasis.
Case Discussion
The limb was amputated and histopathology showed osteosarcoma. The dog was treated with chemotherapy, however developed presumed pulmonary metastasis 9 months after diagnosis.
This lesion is characteristic of a primary bone tumor. The location and expansile, destructive pattern are features to look for. A fungal osteomyelitis would tend to have more productive bone, and is often multifocal. Osteosarcoma is most likely in this case.
Differential diagnoses for primary bone tumor include
osteosarcoma (by far most common)
chondrosarcoma
fibrosarcoma
hemangiosarcoma
liposarcoma
Unable to process the form. Check for errors and try again.