Since we often have members who are dealing with rare forms of certain limb cancers, we just wanted to share this study we came across in the Journal of the American Animal Hospital Association.

Dedifferentiated chondrosarcomais an uncommon but aggressive version of chondrosarcoma. If you're dealing with this diagnosis, the abstract is something you may want to read for background information. See if you can get a copy from your vet in order to read the entire study. 

Dedifferentiated Chondrosarcoma in the Dog and Cat: A Case Series and Review of the Literature.

Abstract

This retrospective case series describes seven dogs and one cat diagnosed with dedifferentiated chondrosarcoma, an uncommon, aggressive variant of chondrosarcoma. The purpose of the study is to describe clinical, imaging, and histopathological findings of this tumor. Medical records and the diagnostic laboratory database at Colorado State University from 2000 to 2015 were reviewed and complete medical records were available for the eight animals in this report. Similar to what has been reported in people, poor long-term survival and high metastatic rate, particularly to the lungs, was observed in our case series. A bimorphic pattern on imaging (radiographs, computed tomography, and MRI) consisting of mineralized and nonmineralized areas was seen mirroring the high-grade sarcomatous component adjacent to a low-grade chondroid component seen histopathologically. A review of the human literature including suspected etiology, imaging findings, histopathology, and survival times with various treatment options is presented. This article describes the first reported cases of dedifferentiated chondrosarcoma in the veterinary literature. Early accurate recognition could lead to treatment plans tailored to this variant.