A 9-year-old spayed female Cane Corso dog was presented with a 1-week history of an acute right hind limb non-weight-bearing lameness. Six years previously, a right tibial tuberosity advancement (TTA) procedure had been performed.
Orthogonal radiographs of the right pelvic limb taken before presentation revealed a comminuted displaced mid-diaphyseal tibial fracture. An aggressive bone lesion with osteolysis and periosteal reaction of the proximal tibia were evident that were most consistent with a primary bone tumor.