Chondrosarcoma Associated With the Appendicular Skeleton of 2 Domestic Ferrets

A 5-year-old male neutered ferret (Mustela putorius) and a 2-year-old male neutered ferret were evaluated for fast growing immobile swellings involving the left hock and the right scapula, respectively. In both cases, serum chemistry was unremarkable and a complete blood count demonstrated mild anemia. In case 1, radiographic evaluation demonstrated increased soft tissue density in the region of the distal tibia and fibular tarsal bone. A fine-needle aspirate demonstrated atypical mesenchymal cells, and an incisional biopsy revealed irregular partly mineralized proliferations of cartilage consistent with chondrosarcoma. Computed tomography was performed, demonstrating attachment of the mass to the distolateral tibial epiphysis. A limb-sparing surgery was performed; however, 5 months following resection local reoccurrence was noted. At 18 months, the ferret underwent a left hind limb amputation. No sign of metastatic disease was reported at 27 months. In case 2, radiographic evaluation demonstrated a poorly organized mineralized soft tissue mass extending from the right acromion to the area surrounding the neck of the scapula. Microscopic evaluation of an incisional biopsy revealed a chondrosarcoma. A forequarter amputation was performed. The ferret died 4 years later with no evidence of local recurrence or the development of metastatic disease. These 2 cases represent the first reports of chondrosarcoma in the appendicular skeleton of 2 ferrets. Based on these 2 cases, local recurrence may be expected unless adequate surgical margins are achieved. The metastatic potential of chondrosarcoma in this species appears to be low.