Spine extra-osseous chordoma mimicking neurogenic tumors: report of three cases and review of the literatures

BACKGROUND For a long time, chordoma has been known as an osseous tumor mainly found at the clivus and sacrococcygeal region. However, spine extra-osseous chordoma (SEC) with a better prognosis than the classic type has been neglected. According to our literature review, only several case reports have been published in English literatures. Here in this article, three cases of SEC, plus a literature review, are presented. CASE PRESENTATION Three cases of SEC were presented from our center. Surprisingly, neurologic tumors were considered as the first diagnosis. Thereafter, en bloc resection was performed in all the three cases. Especially, the dumbbell-shaped one in the cervical spine was removed by en bloc through the combined anterior and posterior approach for the first time. Follow-up within 12-58 months after surgeries proved no recurrence or metastasis. CONCLUSIONS Spine extra-osseous chordoma, commonly located in the cervical and epidural region, is extremely rarely met. SEC is characterized with less aggressiveness, the lower rate of recurrence and metastasis, and better prognosis than those of the osseous origin. Though complete excision can be achieved generally, differential diagnosis of spine neurogenic tumors and the following en bloc resection should be made as carefully as possible.