Long-term surgical outcomes for myxopapillary ependymomas of the cauda equina.
METHODS
Retrospective case series.


OBJECTIVE
To evaluate our treatment strategy for myxopapillary ependymomas of the cauda equina.


BACKGROUND
Some patients with myxopapillary ependymoma develop cerebrospinal fluid (CSF) dissemination leading to poor prognosis. Because of the rarity of this tumor, there is no consensus on its optimal treatment options and prognosis.


METHODS
We reviewed 25 cases of myxopapillary ependymomas, treated surgically between 1972 and 2005. The mean postoperative follow-up period was 10.4 years. The effects of surgical margins at surgery and postoperative radiotherapy on tumor recurrence and prognosis were investigated.


RESULTS
In 15 patients, total resection achieved (6 cases of en bloc resection without postoperative radiation, and in 9 cases piecemeal resection) was followed by whole brain and spinal cord radiation or local irradiation. Fourteen of these patients survived without tumor recurrence. In 1 case of total resection without radiotherapy, the tumor capsule was violated intraoperatively and local recurrence occurred 2 years after surgery. In 4 patients, the tumors were removed subtotally. Of these, 2 patients who received radiation (24 Gy) only to the whole brain and spinal cord developed recurrence, and 2 who received whole brain and spinal cord radiation (24 Gy) supplemented with local radiation (46 Gy) developed no recurrence. The remaining 6 patients received partial resection after local radiation (40-50 Gy) alone, and all 6 died of CSF dissemination.


CONCLUSIONS
The results of the present study indicate that the surgical margin obtained at the initial surgery and the extent and amount of postoperative radiation can be crucial factors determining the prognosis of patients with myxopapillary ependymoma. Although this tumor is histologically benign, CSF dissemination can occur once tumor capsule is violated, before or during surgery. Therefore, early diagnosis is essential, and a therapeutic strategy including radiotherapy, on the assumption that this tumor is malignant, should be established.
Nakamura
Masaya
M
Department of Orthopedic Surgery, School of Medicine, Keio University, Shinjuku, Tokyo, Japan. masa@sc.itc.keio.ac.jp
Ishii
Ken
K
Watanabe
Kota
K
Tsuji
Takashi
T
Matsumoto
Morio
M
Toyama
Yoshiaki
Y
Chiba
Kazuhiro
K
D000293:Adolescent; D000328:Adult; D002420:Cauda Equina / Q000473:pathology; D004806:Ependymoma / Q000175:diagnosis / Q000601:surgery*; D005260:Female; D006801:Humans; D015994:Incidence; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology / Q000517:prevention & control; D019635:Neurosurgical Procedures; D010524:Peripheral Nervous System Neoplasms / Q000175:diagnosis / Q000601:surgery*; D011379:Prognosis; D018714:Radiotherapy, Adjuvant / Q000379:methods; D012189:Retrospective Studies; D016896:Treatment Outcome; D055815:Young Adult