Retropharyngeal chordoma extending to the spinal cord, mimicking a neurogenic tumor: a case report and literature review.

Chordomas are rare, locally aggressive bone malignancies with poor prognoses. However, those with minimal or no bone involvement are more easily resectable because of their well-delineated margins and thus have better prognoses. Such extraosseous chordomas of the spine are localized both intradurally and extradurally. Only a few case reports have focused on extraosseous, extradural spinal chordomas. Radiologically, this type of chordoma has a dumbbell shape; however, dumbbell-shaped spinal tumors are traditionally thought to be neurogenic tumors (i.e., schwannomas or neurofibromas). We herein report a unique case involving a woman with a dumbbell-shaped extraosseous chordoma protruding predominantly into the retropharyngeal space. A 44-year-old woman presented for evaluation of a left submandibular mass. A T2-hyperintense, gadolinium-enhancing mass was found in her cervical spinal canal, protruding through the C2/3 neural foramen into the retropharyngeal space with minimal vertebral involvement. The initial diagnosis was a neurogenic tumor, most likely a schwannoma. After subtotal removal, the pathologic diagnosis was a chordoma. Because chordomas and schwannomas have significantly different prognoses, caution is warranted when a dumbbell-shaped tumor is identified in the spine with minimal or no vertebral deterioration on radiology. This report also provides the first thorough review of extraosseous dumbbell-shaped intraspinal-extraspinal chordomas.