Clinical features and surgical outcomes of intracranial and spinal cord subependymomas

Abstract

OBJECTIVE Subependymomas are low-grade ependymal tumors whose clinical characteristics, radiographic features, and postsurgical outcomes are incompletely characterized due to their rarity. The authors present an institutional case series and a systematic literature review to achieve a better understanding of subependymomas. METHODS Adult patients with histologically confirmed subependymoma or mixed subependymoma-ependymoma surgically treated at a tertiary hospital between 1992 and 2020 were identified. A systematic literature review of the PubMed, Embase, Web of Science, and Google Scholar databases from inception until December 4, 2020, was conducted according to PRISMA guidelines. Data extracted from both groups included demographics, radiographic features, tumor characteristics, management, and follow-up variables. RESULTS Forty-eight unique patients with subependymoma were identified by chart review; of these patients, 8 (16.7%) had mixed subependymoma-ependymoma tumors. The median age at diagnosis was 49 years (IQR 19.8 years), and 26 patients (54.2%) were male. Forty-two patients (87.5%) had intracranial subependymomas, and 6 (12.5%) had spinal tumors. The most common presentation was headache (n = 20, 41.7%), although a significant number of tumors were diagnosed incidentally (n = 16, 33.3%). Among the 42 patients with intracranial tumors, 15 (35.7%) had hydrocephalus, and the most common surgical strategy was a suboccipital approach with or without C1 laminectomy (n = 26, 61.9%). Gross-total resection (GTR) was achieved in 33 cases (68.7%), and 2 patients underwent adjuvant radiotherapy. Most patients had no major postsurgical complications (n = 34, 70.8%), and only 1 (2.1%) had recurrence after GTR. Of 2036 reports initially identified in the systematic review, 39 were eligible for inclusion, comprising 477 patients. Of 462 patients for whom tumor location was reported, 406 (87.9%) were intracranial, with the lateral ventricle as the most common location (n = 214, 46.3%). Spinal subependymomas occurred in 53 patients (11.5%), with 3 cases (0.6%) in multiple locations. Similar to the case series at the authors’ institution, headache was the most common presenting symptom (n = 231, 54.0%) among the 428 patients whose presentation was reported. Twenty-seven patients (6.3%) were diagnosed incidentally, and 36 cases (8.4%) were found at autopsy. Extent of resection was reported for 350 patients, and GTR was achieved in 250 (71.4%). Fifteen of 337 patients (4.5%) had recurrence or progression. CONCLUSIONS The authors’ case series and literature review demonstrate that patients with subependymoma are well managed with resection and generally have a favorable prognosis.

Spinal Cord Subependymoma: A Subanalysis of the Neurospinal Society of Japan’s Multicenter Study of Intramedullary Spinal Cord Tumors

“…In the patients of this series, numbness in the extremities was the most frequent symptom (84.6%), followed by motor paralysis (69.2%), and gait disturbance (61.5%), which is consistent with previous case series [ 1 , 5 , 6 ]. However, modified McCormick grade before surgery was I or II in almost all patients in 2 of these series [ 5 , 6 ]; in contrast, modified McCormick grade was I or II in slightly more than half of patients in this series.…”

“…Central nervous system subependymoma accounts for less than 1% of all intracranial tumors [ 9 , 35 ]. Spinal cord subependymoma is even rarer—only 113 surgical cases have been reported to date in numerous case reports and series [ 1 , 5 - 31 ]. Subependymomas are more common in middle-aged men in the fourth decade of life (mean age, 46 years) and frequently occur in the fourth and lateral ventricles [ 1 ].…”

“…Spinal cord subependymoma is even rarer—only 113 surgical cases have been reported to date in numerous case reports and series [ 1 , 5 - 31 ]. Subependymomas are more common in middle-aged men in the fourth decade of life (mean age, 46 years) and frequently occur in the fourth and lateral ventricles [ 1 ]. In 2 recent case series of spinal cord subependymoma [ 5 , 6 ], most patients were men in their 40s and cervical and cervicothoracic sites were most common.…”

“…Subependymomas are rare, slow-growing, benign central nervous system tumors which predominantly occur in the fourth and lateral ventricles of the brain. Approximately 11% occur in the spinal cord [ 1 - 4 ]. Only 113 cases of spinal cord subependymoma have been reported since 1954 [ 1 , 5 - 32 ]; therefore, data regarding appropriate treatment, surgical outcomes, and long-term prognosis are limited.…”

“…Approximately 11% occur in the spinal cord [ 1 - 4 ]. Only 113 cases of spinal cord subependymoma have been reported since 1954 [ 1 , 5 - 32 ]; therefore, data regarding appropriate treatment, surgical outcomes, and long-term prognosis are limited. Although this tumor is a histologically benign lesion and can be cured by complete surgical resection, a surgical strategy that considers the preservation of neurological function is required at the same time.…”