Elsevier

World Neurosurgery

Volume 106, October 2017, Pages 60-73
World Neurosurgery

Original Article
The Clinical Features and Surgical Outcomes of Spinal Cord Tanycytic Ependymomas: A Report of 40 Cases

https://doi.org/10.1016/j.wneu.2017.06.111Get rights and content

Objective

Spinal cord tanycytic ependymomas (TEs) rarely are reported because of extremely low incidence. Understanding of this disease is therefore poor. The aim of this study was to analyze the incidence and clinical, radiologic, pathologic, and prognostic features of spinal cord TEs.

Methods

Approximately 4000 spinal cord tumors were resected surgically in Beijing Tiantan Hospital between April 2009 and May 2016. We identified all cases of pathologically proved TEs among these patients.

Results

TEs accounted for approximately 1% of spinal cord tumors (40 of an estimated 4000). Patients with TE were a mean age of 40.0 years and had no significant sex preference (21 male and 19 female). The median diameter of the maximal tumor was 54.2 mm (range, 16–153 mm). The mean preoperative Japanese Orthopedic Association (JOA) score was 13.0. Radiologically, 47.5% (19/40) cases showed poorly defined tumor border, and 40% (16/40) of them showed preoperative syringomyelia. Gross total resection was achieved in 30 cases, subtotal resection in 8, and partial resection in 2. At the time of discharge, JOA score and neurologic function showed improvement in 26 cases (65%), no change in 12 cases (30%), and worsening in 2 cases (5%). At a median follow-up of 43 months (range, 7–101 months), 1- and 5-year progression-free survival rates were 100.0% and 97.5%, respectively. Only one patient had tumor recurrence which was found 30 months after surgery. No patient died of tumor recurrence. At the latest follow-up, JOA score showed improvement in 30 cases (75%), no change in 8 cases (20%), and worsening in 2 cases (5%). Univariate analysis revealed that tumor size and preoperative JOA score were significantly associated with the short-term outcomes. Meanwhile, age ≥40 years, tumor size ≥50 mm, non-gross total resection, and preoperative JOA score <14 were significantly associated with an increased risk of worsened long-term outcomes. Poorly defined tumor border and preoperative JOA score <14 significantly limited the extent of tumor resection.

Conclusions

Spinal cord TE is a rare subtype of ependymomas with low recurrence. Long-term survival can be expected, although poorly defined tumor border is an independent predictor of long-term outcomes. Microsurgical treatment of spinal cord TEs remains a formidable challenge due to the poorly defined border and critical neurovascular structures encasement. It is unnecessary for radical tumor resection at the cost of severe neurologic deficits.

Introduction

Tanycytic ependymoma (TE) is a rare subtype of World Health Organization (WHO) grade II ependymoma, most frequently found in cervical and thoracic spinal cord.1 TE usually originates from the ependymal cells of brain ventricular wall and is characterized by elongated spindle cells.2 Clinically, it often is diagnosed mistakenly as a spindle cell tumor of central nervous system. TE was first described and named by Friede and Pollak in 1978, and only 34 cases have been described since then.3 As the result of the sparse reporting of spinal cord TE, their clinical characteristics and surgical outcomes remain largely unknown. To learn more about the clinical, radiologic, and pathologic features and prognosis of this rare disease, we present analysis from a consecutive cohort of 40 patients with histologically proven spinal cord TE in one of the largest neurosurgical centers of China.

Section snippets

Patient Cohort

This retrospective study was approved by Institutional Review Board of Beijing Tiantan Hospital, Capital Medical University, Beijing, China. Review of the records of Beijing Tiantan Hospital for the period from 2009 to 2016 identified 40 patients who had undergone microsurgery in our department and were pathologically confirmed to be spinal cord TE.

Record of Clinical and Radiologic Material

The clinical data and operation records of the patients with spinal cord TE were reviewed retrospectively. All patients had undergone pre- and

Incidence and Clinical Features of Spinal Cord TEs

In total, 40 cases of pathologically confirmed spinal cord TE were identified among the approximately 4000 cases of surgically spinal cord tumors. Therefore, the incidence of spinal cord TE is approximately 1%.

Patient demographics and baseline characteristics are summarized in Tables 2 and 3. The patients had a mean age of 40.0 years at diagnosis and ranged from 22 to 69 years. No sex preference was found in these patients, with 21 male and 19 female patients included. The duration from onset

Discussion

Spinal cord TE is a rare neoplasm of the central nervous system that often is misdiagnosed as other diseases. To date, few cases of spinal cord TE have been reported because of its extremely low incidence. We searched approximately 4000 patients with spinal cord tumors resected in our hospital from in the past 8 years and found 40 cases were pathologically confirmed as spinal cord TEs. To the best of our knowledge, this is the largest series of spinal cord TEs from a single neurosurgical center.

Conclusions

Spinal cord TEs accounted for approximately 1% of spinal cord neoplasms and showed nonspecific radiologic features. GTR can be achieved in most cases and long-term survival can be expected. Poorly defined border is an independent risk factor for non-GTR, and is valuable in surgical plan.

Acknowledgments

We thank all the patients who trusted us and all the physicians and staff who helped this study.

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    Conflict of interest statement: The authors declare that the article content was composed in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

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