We thank Dr. Khalil and colleagues for their comments [1]. We agree that the discovery of the fusion testing in mesenchymal chondrosarcoma can be helpful in confirming its diagnosis, particularly in difficult cases. At the time of this case, testing for this fusion was not clinically validated at our institution nor at our outside vendors. Hence this case was reviewed in consensus with pathologists who specialize in bone and soft tissue pathology to arrive at the diagnosis. It is true that molecular testing with its increasing availability now can be helpful in establishing diagnosis of mesenchymal chondrosarcomas, particularly those with less than optimal pathologic features or sampling. We intend to make use of testing for HEY1-NCOA2 fusion transcript in the future in our difficult cases.

Rajendra Kumar, M.D.