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Year : 2012  |  Volume : 60  |  Issue : 4  |  Page : 379--384

Lateral ventricular subependymomas: An analysis of the clinical features of 27 adult cases at a single institute

Zonggang Hou1, Zhen Wu2, Junting Zhang2, Liwei Zhang2, Runfa Tian2, Baiyun Liu2, Zhongcheng Wang3,  
1 Department of Neurosurgery, Beijing Neurosurgical Institute, Capital Medical University, Beijing; Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
2 Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
3 Department of Neurosurgery, Beijing Neurosurgical Institute, Capital Medical University, Beijing, China

Correspondence Address:
Zhongcheng Wang
Department of Neurosurgery, Beijing Neurosurgical Institute, Capital Medical University, Tiantan Xili 6, Dongcheng District, Beijing, 100050


Objective: To evaluate the unique clinical characteristics and management of lateral ventricular subependymomas (LVSs). Patients and Methods : The case records of 27 adult consecutive patients with LVS admitted between March 1996 and May 2011 were reviewed. The relevant clinical data (including patient age and sex, neuroimaging studies, surgical records and follow up) were collected through a chart review. Patient neurological status was recorded using the Karnofsky Performance Scale (KPS). Results: The gender distribution was 14:13 and the age from 33 to 66 years (median 45 years) at the time of operation. Headache and dizziness were the most common initial symptoms (17/27). Most of these tumours were located at the foramen of Monro (12/27). Magnetic resonance imaging (MRI) (21/27) showed well circumscribed tumours with cystic changes (21/27). The lesions were hypointense on T1-weighted images (19/21), hyperintense on T2-weighted images (21/21), and contrast enhancement was no or minimal (19/21). Gross total resection was performed in 23 patients. Five patients required a ventriculo-peritoneal shunt because of postoperative hydrocephalus. The follow-up period ranged from 6 to 188 months (mean 55.5 months). No recurrence was observed during the follow up. Conclusion: In this study LVSs had equal gender distribution. Tumours around the foramen of Monro were the candidates for aggressive treatment; surgery was the best curative treatment; postoperative hydrocephalus should be attended to.

How to cite this article:
Hou Z, Wu Z, Zhang J, Zhang L, Tian R, Liu B, Wang Z. Lateral ventricular subependymomas: An analysis of the clinical features of 27 adult cases at a single institute.Neurol India 2012;60:379-384

How to cite this URL:
Hou Z, Wu Z, Zhang J, Zhang L, Tian R, Liu B, Wang Z. Lateral ventricular subependymomas: An analysis of the clinical features of 27 adult cases at a single institute. Neurol India [serial online] 2012 [cited 2021 Dec 5 ];60:379-384
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Full Text


Subependymomas are rare, noninvasive, slow-growing tumours and occur most commonly in middle-aged and elderly men. [1] Most frequently are located in the fourth and lateral ventricles. [2],[3] Only a few larger case series have focused only on lateral ventricular subependymomas (LVSs). [2],[4],[5],[6],[7] In this paper, we review our experience of 27 cases of LVSs.

 Patients and Methods

Between March 1996 and May 2011, 27 adult patients (14 females, 13 males) underwent surgery for LVS at the Department of Neurosurgery in Beijing Tiantan Hospital. The relevant clinical data (including patient age and sex, neuroimaging studies, surgical records and follow up) were collected through a chart review and telephone interviews. Radiological reports and surgical records were considered for analysis when the preoperative or postoperative films were unavailable for review. Gross total resection (GTR) was defined as total macroscopic removal of the tumor mass and subtotal resection (STR) as subtotal macroscopic tumor removal. The estimation of the extent of tumor removal was primarily the responsibility of the neurosurgeons, but was also validated by reviewing the post-surgical magnetic resonance imaging (MRI). Postoperative neurological status was assessed using the Karnofsky performance scale (KPS).


Clinical presentation

The clinical characteristics of the 27 patients are summarised in [Table 1]. Age ranged from 33 to 66 years (median 45 years) and average age at the time of presentation was more for men than for women (48 vs. 42 years). The duration of symptoms ranged from two weeks to three years (median 24 mos.). Headache and dizziness were the most common initial symptoms.{Table 1}

Location and size

Location of the tumours was: left lateral in 12 patients, right lateral in 12 patients, bilateral in 3 patients. Intraventricular location was: foramen of Monro in 12 patients, septum pellucidum in 7 patients, trigone of the lateral ventricle in 6 patients, and both the lateral and third ventricles in two patients [Cases 7, 16; [Figure 1]]. Tumour size ranged from 1.5 cm to 7.3 cm (median 4.0 cm). Four tumours were less than 3.0 cm in the greatest dimension, 19 were between 3.0 cm and 5.0 cm, and 4 were greater than 5.0 cm. The size of symptomatic subependymomas around the foramen of Monro was relatively small (mean 2.9 cm).{Figure 1}

Neuroradiological findings

Preoperative computer tomography (CT) results were available in seven patients, and MRI results were available in 21 patients [Table 2]. Hydrocephalus was noted in 23/27 (85%) patients. The CT scans in 7 patients demonstrated nodular masses with cystic changes and no calcification in the intraventricular location. The lesions were hypo-dense in 4 cases and iso-dense in 3 cases. Only one of the 7 patients had CT contrast imaging and it demonstrated mineral enhancement. MRI revealed well circumscribed lesions and cystic degeneration was noted in 19/21 tumours. Peritumoral oedema was observed in 2 patients [Cases 3, 10; [Figure 2]]. T1-weighted images revealed a hypointense signal in 19/21 patients and an isointense signal in 2/21 patients. T2-weighted imaging showed a hyperintense signal in all the patients. Administration of contrast resulted in no to minimal enhancement in most subependymomas (19/21). Moderate enhancement was observed in one tumour, and bright contrast enhancement was observed in one case [Case 3; [Figure 2]].{Table 2}{Figure 2}

Histological findings

A histological examination showed that the tumour cells were of low cellularity with an alternating appearance of hypocellular and cellular portions. Tumour cell nuclei, which were round to ovoid nuclei, were grouped in clusters and embedded in a fibrillary matrix of cell processes with the frequent occurrence of small cysts [Figure 3].{Figure 3}

Operative findings and outcomes

All patients underwent a craniotomy for tumour removal. Intraoperatively, the tumours typically appeared as hypo-vascular, greyish white, smooth-surfaced, rubbery masses. All tumours were located in the ventricles without extension into the brain parenchyma. Tumours were found attached to the septum pellucidum in 10 patients, the lateral ventricular wall in 9 patients, the thalamus in 6 patients, the caudate nucleus wall in 1 patient, and the roof of the third ventricle in 1 patient. Gross total resection was performed in 23 patients and subtotal resection in the 2 trigonal tumours (Cases 9 and 14), in 1 bilateral ventricular tumour (Case 6) and in 1 right septum pellucidum tumour (Case 10), due to limited exposure along the ventricular walls and profuse bleeding. Postoperatively, 1 patient (Case 8) died of intraventricular haemorrhage, 1 patient (Case 10) had a postoperative haemorrhage and infection and 1 patient (Case 26) had a postoperative subdural effusion. The follow up data were available for 26 of the 27 patients. The mean follow-up was 55.5 months (range: 6-188 months). None of the 26 patients showed tumour recurrence at the time of follow up. Five patients (Cases 1, 6, 11, 14 and 21) developed hydrocephalus postoperatively and required a ventriculo-peritoneal shunt. No adjuvant therapy was prescribed. At follow-up, most patients had KPS scores that were higher or equivalent to their preoperative values (24/26). Only three patients exhibited a poor KPS.


Subependymomas are rare and only a few series of LVSs have been published [1],[2],[3],[4], [7],[8],[9],[10],[11],[12],[13],[14],[15] [Table 3]. Of the 83 cases of subependymomas in the series by Rushing et al., 36 were located in the lateral ventricle and a limited clinical data were provided. [8] Ragel et al. [3] reported 16 cases of subependymomas with only 3 cases located in the lateral ventricle. Our series adds 27 patients, which is a significant number, to the existing literature. Analysis of the published data on LVS reveals some unique characteristics in these patients. {Table 3}

Subependymomas occur most commonly in middle-aged and elderly men. [1] The gender distribution in the published case series was somewhat similar and if at all more in women. This was more so in the series from Asian countires [Table 3]. The mean age of the patients in our series was 45 years and the gender distribution was almost equal in either sex. LVS can be asymptomatic all the life. Many cases are detected incidentally. The presenting symptoms can be divided into symptoms caused by CSF obstruction (e.g., headache, nausea, vomiting, altered consciousness) or those attributable to the compression of neural structures (e.g., complaints of sensory symptoms, motor weakness, seizure). In our case series, headache and dizziness were the most common initial symptoms. Tumour location and size are critical factors for presenting symptoms. Tumours smaller than 2 cm in diameter are generally asymptomatic but may become symptomatic when they grow to 3-5 cm in size, [16] which was also the observation in our series. However, subependymomas around the foramen of Monro should be handled carefully regardless the size as the tumour in this location can casue acute hydrocephalus. [16],[17] The mean size of the subependymomas around the foramen of Monro with symptoms in our patients was 2.9 cm.

In this study on neuroimaging subependymoma were well demarcated with nodular appearance with no side dominance as seen in our series. Within the ventricle, LVSs were most commonly located at foramen of Monro. Hydrocephalus was noted in 85% of patients. The proportion of symptomatic patients with hydrocephalus was 87.5%, which is similar to the 88% reported by Scheithauer. [1] On CT majority of LVSs appear as well-defined iso-or hypo-dense intraventricular masses with no to minimal contrast enhancement. [4],[11] Calcification is not commonly found in association with LVS, [18] as the case in our series. On MRI LVSs are lobulated intraventricular masses with rare paraventricular extension and frequent intratumoural cyst formation. [2],[4],[14],[19] These lesions are hypo-to iso-intense on T1-weighted images and hyperintense on T2-weighted images; with little to no enhancement enhancement. [3],[4],[14],[19],[20] Peritumoral oedema, dense enhancement, and intratumour haemorrhage are somewhat rare. [2],[11],[20],[21],[22] Among our cases, we found only two tumours with peritumoural oedema, one tumour with moderate enhancement, and one tumour with obvious contrast enhancement. The differential diagnosis of a lateral ventricular mass included choroid plexus papilloma, central neurocytoma, subependymal giant cell astrocytoma, meningioma, metastasis and ependymoma. [23] Although the signal characteristics and contrast enhancement pattern are non-specific, if the imaging findings are examined together with the patient's age, gender and the specific location of the tumour within the ventricle, the preoperative diagnosis of subependymoma is still possible in most cases.

Subependymomas often carry a good prognosis, and complete surgical removal is typically curative for LVSs. The treatment options for LVSs include both 'watchful waiting' and surgical resection. [3] In asymptomatic patients, serial imaging is reasonable. Some authors argue in favour of surgery for such cases for the following reasons: benign biological behaviour of the tumour, the potential for a surgical cure, and the desire to avoid the risk of symptom worsening or even death because small tumours may unexpectedly become symptomatic. [16] Two of three asymptomatic patients in our series exhibited hydrocephalus, which implies the need for aggressive treatment. Surgery is indicated for the establishment of a pathological diagnosis or the decompression of neural elements. Intraoperatively, subependymomas are often found to be rubbery in consistency and greyish white in colour. [14],[24] Expansive growth into the ventricle rather than an infiltrative growth into the parenchyma, hypovascularity, and sharp demarcation from the surrounding brain are also typical characteristics of LVSs. [2],[14] Large subependymomas often have several sites of attachment, and surgeons must exercise care to avoid damage to adjacent structures. Some tumours may be markedly lobulated and hypervascular and have limited exposure along the ventricular walls, and the subtotal removal of such tumours often results in a favourable outcome. Meanwhile, if the ventricles are of adequate size, the endoscope can be used to remove or to assist in the removal of LVSs. [25],[26] Although postoperative morbidity is rare, the reported complications include hydrocephalus, meningitis, and sepsis. [2],[10],[11],[14],[19] Among our patients, one died of an intraventricular haemorrhage, one experienced postoperative haemorrhage and infection, one exhibited postoperative subdural effusion, and five (5/27) postoperatively developed hydrocephalus requiring a ventriculo-peritoneal shunt operation. Hydrocephalus should be given more attention.


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