6 year old Labrador Retriever

Findings

There is a granular, mineralized mass present on the occipital bone of the skull and projecting caudally. The cortical margins are lytic in the region of the mass. Although the calavarium appears normal, the mass may be present within it, which would be better assessed on CT images. The soft tissues dorsal to the mass are distorted. The remainder of the osseous and soft tissue structures of the head are normal.

Findings

• Multilobular osteochondrosarcoma (typical location and appearance)
• Osteosarcoma
• Other primary bone tumor