Sinonasal chondromyxoid fibroma.

Chondromyxoid fibroma (CMF) is a rare benign cartilaginous tumor that usually arises from the metaphysis of long bones. In rare cases, however, CMF presents in unusual locations, such as the facial bones and sinonasal tract. We present a case of a 60-year-old woman with a CMF of the nasal septum. The initial radiographic findings were suggestive of a vascular tumor or a malignancy, but microscopic examination revealed the typical pathologic features of CMF, and SOX9 immunostaining confirmed its cartilaginous origin. The tumor was successfully excised, and the patient was free of disease at 12-month follow-up. Recognizing CMF is important when it presents in unexpected locations, especially because of its histologic resemblance to chondrosarcoma. We believe that the use of SOX9 in our case assisted in the recognition of the chondroid nature of the lesion and facilitated the diagnosis of CMF.