Today’s case is a 2-year-old male Akita with progressive right pelvic limb lameness and swelling. What are your differential diagnoses?
There is mixed osteolysis and new bone production of the right proximal tibial metaphysis and epiphysis. There is lysis of the cortical bone of the tibial plateau. The lesion has a medium zone of transition. There is markedly increased soft tissue opacity surrounding the proximal tibia and in the region of the infrapatellar fat pad. The remainder of the pelvic limb appears normal.
- primary bone tumor
- histiocytic sarcoma
- synovial cell sarcoma
Ultrasound guided fine needle aspirate was performed. Cytology was performed with the diagnosis of sarcoma, with fibroblastic osteosarcoma as a primary differential diagnosis.