Intradural Extramedullary Nonconus Nonfilum Spinal Ependymomas: Report of a Rare Variant and Newer Insights into Their Histogenesis with Proposal of a Classification Scheme and a Management Algorithm Based on a Review of Literature

Kuntal Kanti Das; Gagandeep Attri; Suyash Singh; Kamlesh Singh Bhaisora; Pawan Verma; Sushila Jaiswal; Awadeshkumar Jaiswal; Sanjay Behari

doi:10.1016/j.wneu.2019.10.152

Intradural Extramedullary Nonconus Nonfilum Spinal Ependymomas: Report of a Rare Variant and Newer Insights into Their Histogenesis with Proposal of a Classification Scheme and a Management Algorithm Based on a Review of Literature

World Neurosurg. 2020 Feb:134:323-336. doi: 10.1016/j.wneu.2019.10.152. Epub 2019 Nov 1.

Authors

Kuntal Kanti Das¹, Gagandeep Attri², Suyash Singh², Kamlesh Singh Bhaisora², Pawan Verma³, Sushila Jaiswal³, Awadeshkumar Jaiswal², Sanjay Behari²

Affiliations

¹ Department of Neurosurgery, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India. Electronic address: kkdas@sgpgi.ac.in.
² Department of Neurosurgery, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India.
³ Department of Neurosurgery, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India; Department of Pathology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India.

PMID: 31682991
DOI: 10.1016/j.wneu.2019.10.152

Abstract

Background: Ependymomas are common intramedullary spinal tumors but there are scattered reports of this tumor presenting with exophytic growth patterns masquerading as intradural extramedullary (IDEM) tumors. Such IDEM ependymomas are seldom suspected preoperatively and it is only during surgery that their existence is revealed. Little is known of such rare growth patterns of an otherwise common intramedullary spinal cord tumor, their characteristics, and their management considerations.

Methods: We present a case of an exophytic dorsal ependymoma with a stalk like attachment to the spinal cord and the surgical management in a 24-year old woman. An extensive literature search was carried out on all prominent databases to find out similar cases reported earlier. We excluded filum/conus ependymoma, purely extradural spinal ependymoma as well as the extraspinal ependymomas. Details of each case reported before were obtained and tabulated.

Results: IDEM ependymomas have been reported in 54 patients so far, including the present case. Four patterns of growth emerged from the literature review: intramedullary ependymoma with exophytic component (group I, n = 9), exophytic IDEM ependymoma without intramedullary component (group II, n = 6), IDEM ependymoma arising from nerve roots (group III, n = 7), and pure IDEM ependymoma (group IV, n = 32). Except in group I, IDEM ependymoma affects females more frequently, without any specific age predilection. Thoracic spinal cord/canal is the most common location across all groups. Multifocal disease, craniospinal dissemination, and recurrences tend to be maximum in group IV.

Conclusions: IDEM ependymomas are more common in thoracic segment of the cord and broadly divisible into 4 subgroups. We suggest a subpial origin of group II IDEM ependymomas. We also advocate proliferation index estimation in grade II ependymomas to enable formulation of an optimal management plan.

Keywords: Exophytic growth; Outcome; Pathology; Radiology; Spinal ependymoma; Surgery.

Publication types

Case Reports
Review

MeSH terms

Algorithms
Ependymoma / classification
Ependymoma / pathology*
Ependymoma / surgery*
Female
Humans
Spinal Cord Neoplasms / classification
Spinal Cord Neoplasms / pathology*
Spinal Cord Neoplasms / surgery*
Young Adult