Subependymomas of the fourth ventricle: To operate or not to operate?

BACKGROUND: There is a paucity of literature regarding the clinical characteristics and management of subependymomas of the fourth ventricle due to their rarity. Here, we describe the operative and non-operative management and outcomes of patients with such tumors. METHODS: This retrospective single-institution case series was gathered after Institutional Review Board (IRB) approval. Patients diagnosed with a subependymoma of the fourth ventricle between 1993 and 2021 were identified. Clinical, radiology and pathology reports along with magnetic resonance imaging (MRI) images were reviewed. RESULTS: Patients identified (n = 20), showed a male predominance (n = 14). They underwent surgery (n = 9) with resection and histopathological confirmation of subependymoma or were followed with imaging surveillance (n = 11). The median age at diagnosis was 51.5 years. Median tumor volume for the operative cohort was 8.64 cm3 and median length of follow-up was 65.8 months. Median tumor volume for the non-operative cohort was 0.96 cm3 and median length of follow-up was 78 months. No tumor recurrence post-resection was noted in the operative group, and no tumor growth from baseline was noted in the non-operative group. Most patients (89 %) in the operative group had symptoms at diagnosis, all of which improved post-resection. No patients were symptomatic in the non-operative group. CONCLUSIONS: Surgical resection is safe and is associated with alleviation of presenting symptoms in patients with large tumors. Observation and routine surveillance are warranted for smaller, asymptomatic tumors.

Intramedullary Subependymoma Of Lower Thoracic Cord.

Spinal subependymoma (SSE) is a rare intramedullary, benign tumour. Surgical excision isthe preferred approach. However, the interwoven pattern of neural tissue within the tumour dictates the extent of resection. Where gross total resection is linked with possible neurological deficits, subtotal resection or close observation may support better functional outcomes. The evidence for the management of SSE is based mostly on case reports. Herein, we review the existing literature regarding treatment options and clinical outcomes of spinal subependymoma.

The Ribbon Sign as a Radiological Indicator of Intramedullary Spinal Cord Subependymomas.

OBJECTIVE: Intramedullary spinal cord (IMSC) subependymomas are rare World Health Organization grade 1 ependymal tumors. The potential presence of functional neural tissue within the tumor and poorly demarcated planes presents a risk to resection. Anticipating a subependymoma on preoperative imaging can inform surgical decision-making and improve patient counseling. Here, we present our experience recognizing IMSC subependymomas on preoperative magnetic resonance imaging (MRI) based on a distinctive characteristic termed the "ribbon sign." METHODS: We retrospectively reviewed preoperative MRIs of patients presenting with IMSC tumors at a large tertiary academic institution between April 2005 and January 2022. The diagnosis was confirmed histologically. The "ribbon sign" was defined as a ribbon-like structure of T2 isointense spinal cord tissue interwoven between regions of T2 hyperintense tumor. The ribbon sign was confirmed by an expert neuroradiologist. RESULTS: MRIs from 151 patients were reviewed, including 10 patients with IMSC subependymomas. The ribbon sign was demonstrated on 9 (90%) patients with histologically proven subependymomas. Other tumor types did not display the ribbon sign. CONCLUSION: The ribbon sign is a potentially distinctive imaging feature of IMSC subependymomas and indicates the presence of spinal cord tissue between eccentrically located tumors. Recognition of the ribbon sign should prompt clinicians to consider a diagnosis of subependymoma, aiding the neurosurgeon in planning the surgical approach and adjusting the surgical outcome expectation. Consequently, the risks and benefits of gross-versus subtotal resection for palliative debulking should be carefully considered and discussed with patients.

Third Ventricular Subependymomas: Clinical Features and Outcomes Over Two Decades.

BACKGROUND: Subependymomas are uncommon, benign slow-growing neoplasms of the central nervous system preferentially arising within the fourth and lateral ventricles. Third ventricle involvement has been described rarely. The aim of this study is to provide the first systematic review of third ventricular subependymomas (TVSE) by analyzing all reported cases over 2 decades and describing a case example. METHODS: MEDLINE and Embase databases were searched for the 20 years ending January 1, 2022, using relevant MeSH and non-MeSH terms, including "subependymoma" and "third ventricle." Methodology followed PRISMA guidelines. RESULTS: Of 804 identified studies, 131 met inclusion eligibility. The literature yielded 17 patients with TVSE plus our example (18 total). Of these patients, 83% (15/18) presented in adulthood (average age, 42 ± 19 years), of whom 73% were women. The pediatric cohort age was 5 ± 1 years, 67% (4/6) of whom were girls. The most common presenting symptom in both cohorts was headache (80%), followed by memory disturbances and vomitus. In adults, symptomatic tumors were approached by open craniotomy in all but 1 case, most using a transcallosal approach. Gross total resection was obtained in 73%. A ventriculoperitoneal shunt was inserted in 2/15 adult and 4/6 pediatric patients. Overall, both cohorts showed symptomatic improvement without disease recurrence. One patient died perioperatively. CONCLUSIONS: Subependymomas should be considered in the differential diagnosis of third ventricular tumors. The clinical presentation of TVSE mainly parallels hydrocephalus symptoms and, hence, awareness is of vital importance for timely treatment. The surgical goal should be gross total resection, which can be curative and offers greatest clinical improvement across the population.

Imaging characteristics of 4th ventricle subependymoma.

PURPOSE: Subependymomas located within the 4th ventricle are rare, and the literature describing imaging characteristics is sparse. Here, we describe the clinical and radiological characteristics of 29 patients with 4th ventricle subependymoma. METHODS: This is a retrospective multi-center study performed after Institutional Review Board (IRB) approval. Patients diagnosed with suspected 4th ventricle subependymoma were identified. A review of clinical, radiology, and pathology reports along with magnetic resonance imaging (MRI) images was performed. RESULTS: Twenty-nine patients, including 6 females, were identified. Eighteen patients underwent surgery with histopathological confirmation of subependymoma. The median age at diagnosis was 52 years. Median tumor volume for the operative cohort was 9.87 cm3, while for the non-operative cohort, it was 0.96 cm3. Thirteen patients in the operative group exhibited symptoms at diagnosis. For the total cohort, the majority of subependymomas (n = 22) were isointense on T1, hyperintense (n = 22) on T2, and enhanced (n = 24). All tumors were located just below the body of the 4th ventricle, terminating near the level of the obex. Fourteen cases demonstrated extension of tumor into foramen of Magendie or Luschka. CONCLUSION: To the best of our knowledge, this is the largest collection of 4th ventricular subependymomas with imaging findings reported to date. All patients in this cohort had tumors originating between the bottom of the body of the 4th ventricle and the obex. This uniform and specific site of origin aids with imaging diagnosis and may infer possible theories of origin.

Spinal cord subependymoma mimicking syringomyelia in a child: a case report.

Spinal cord subependymomas (SCSEs) in children are extremely rare, and no reports distinguishing SCSEs from syringomyelia have been published. We report a case of a 10-year-old boy who presented with torticollis, scoliosis, as well as pain that had begun in the posterior portion of the neck and progressed to the right shoulder and upper arm. Magnetic resonance imaging showed an intramedullary cyst-like lesion with the same signal intensity as that of cerebrospinal fluid. Idiopathic syringomyelia with scoliosis was first suspected, and a syrinx-subarachnoid space shunt was performed. After surgery, the lesion was slightly smaller; however, 2 years after surgery, it had re-grown, causing excruciating pain but no other symptoms. A second surgery was performed, and gross total resection was achieved. Pathological evaluation revealed SCSE. SCSE needs to be considered as a differential diagnosis for spinal centric cyst-like lesions in children.

A rare case of intraparenchymal subependymoma in a child.

Subependymoma is a slow-growing, exophytic, intraventricular glial neoplasm that commonly arises in the ventricular system. However, a report found that the frequency of intracerebral subependymoma was 0.4% in 1000 routine autopsies. To the best of our knowledge, only seven cases of intracerebral subependymoma have been reported. We report a rare case of intracerebral subependymoma in a child. An 11-year-old girl with generalized tonic-clonic seizures visited the emergency room and had an intraparenchymal tumor on the left frontal lobe on magnetic resonance imaging (MRI). Craniotomy with gross total removal was performed without any perioperative morbidities. The tumor was finally histopathologically diagnosed as a subependymoma.

FROM ERECTILE DYSFUNCTION TO BRAIN SUBEPENDYMOMA: A CASE REPORT.

Endocrinopathies are relatively rare causes of erectile dysfunction. Cases of hyperprolactinemia and pituitary adenomas have been previously reported. We present a clinical case of a 27-year-old male with suspected infertility and recent symptoms of erectile dysfunction. Additional radiological and endocrinologic workup revealed underlying subependymoma, which was expanding in the sellar and suprasellar regions, causing pressure against the pituitary gland. The resulting endocrine disorder caused problems that were subjectively at first manifested mainly as erectile dysfunction. The case is an educative example pointing to the need of taking possible intracranial lesions in consideration when starting workup in a patient presenting with erectile dysfunction. It may be of broad clinical interest not only for endocrinologists but also for practitioners in various fields.

Subependymoma of the Conus Medullaris with Cystic Formation: Case Report and a Literature Review.

BACKGROUND: Subependymoma in the spinal cord is very rare and usually occurs in the cervical cord. We report an exceptional case of subependymoma that occurred at the conus medullaris with cystic formation. This article reviews the literature on subependymoma in the conus medullaris; discusses its clinical manifestations, imaging findings, and differential diagnoses; and offers an opinion about the cystic formation of the subependymoma. CASE DESCRIPTION: A 69-year-old woman experienced progressive limb weakness with a somatosensory abnormality for 3 months. Preoperative magnetic resonance imaging showed a cystic intramedullary lesion at the conus medullaris with a well-defined margin. A preliminary diagnosis of epidermoid cyst was made based on the imaging findings. During the operation, cystic formation of the tumor was found, and the tumor was completely removed. Pathology showed an uneven proliferation of glial cells, consistent with subependymal morphology, and the tumor was confirmed as subependymoma. CONCLUSIONS: We present an extremely rare case of cystic formation in subependymoma at the conus medullaris. Subependymoma should be included in the differential diagnosis of intramedullary cystic lesions. The breakdown of the blood-brain barrier and excessive extravasation may be potential mechanisms of cystic formation.

Microsurgical Resection of the IV Ventricle Subependymoma: 2-Dimensional Operative Video.

In this video, we demonstrate microsurgical resection of IV ventricle subependymoma. To the best of our knowledge, this is the first video case report of a microsurgical resection of subependymoma of the IV ventricle in the peer-reviewed English literature. Subependymomas are benign central nervous system tumors, typically arising in ventricular spaces, mostly in the IV and lateral ventricles.1-3 They are isointense on T1 and hyperintense on T2-weighted magnetic resonance imaging (MRI) with minimal or no enhancement.4 Microsurgery remains the mainstay treatment. Complete tumor resection is possible and curative with excellent prognosis.1,5-7 Although the clinical course appears benign, the inability to diagnose them radiographically with certainty and the possibility of an alternative malignant lesion support a low threshold for early and safe resection.8 A 39-yr-old man presented with severe headache and balance problems. Pre- and postcontrast neuroaxis MRI revealed a centrally located IV ventricle lesion without hydrocephalus. The aim of the surgery was complete tumor resection. Surgery was performed in the prone position by the senior author (KIA) with intraoperative neurophysiology monitoring. A small suboccipital craniotomy and C1 posterior arch removal was done. After opening the dura and arachnoid membrane, the tumor was identified and meticulously dissected from the adjacent posterior inferior cerebellar artery and the floor of the fourth ventricle and from brain stem white matter at the tumor-neural tissue interface to avoid brainstem interference. Histological analysis revealed subependymoma (World Health Organization Grade I). Postoperative pre- and postcontrast MRI revealed complete resection. Headache and balance problems completely resolved; the patient was neurologically intact. The patient provided written consent and permission to publish his image.

Unusual Exophytic Appearance of Spinal Cord Subependymoma.

BACKGROUND: Subependymomas are rare in the spinal cord. They are typically expansile, intramedullary spinal cord masses, eccentrically located with minimal gadolinium enhancement. CASE DESCRIPTION: We present a case of subependymoma originating from the cervical cord with an unusual exophytic appearance. Hallmarks of subependymoma and treatment are reviewed. CONCLUSIONS: This is the first case, to our knowledge, where imaging revealed a mass appearing to be completely extramedullary with a primary exophytic component. Therefore, subependymomas should remain on the differential for masses in the spinal cord that appear extramedullary and exophytic.

Flexible Fiber CO2 Laser in Microsurgical Treatment of Intraventricular Tumors: Usefulness and Limitations.

OBJECTIVE: To assess usefulness and limitations of flexible fiber carbon dioxide (CO2) laser in the microsurgical treatment of intraventricular tumors. METHODS: We reviewed a series of 9 patients treated with microsurgical resection of intraventricular tumors using a flexible fiber CO2 laser. The lesions involved the third ventricle (8) and the frontal horn of the right lateral ventricle (1). Histology revealed 6 craniopharyngiomas, 1 pituitary macroadenoma, 1 subependymoma, and 1 neurocytoma. In all cases, an interhemispheric transcallosal approach was performed. The laser was used during callosotomy, fornix column sectioning, tumor debulking, and to facilitate tumor dissection. We used a 5-tiered score system to assess laser's efficacy in each surgical step (approach, dissection, debulking): grade 1: laser was not at all helpful, grade 5: laser was extremely helpful. Limits of the instrument also are discussed. RESULTS: Gross total resection was achieved in 6 cases and subtotal resection in the remaining 3. Three patients had pulmonary complications treated without clinical sequelae. No laser-related complication was described. Mean utility score observed was 4.2 (range 3-5) during approach, 2.8 (range 2-4) during tumor dissection; and 3.3 (range 2-5) during tumor debulking. Main limits were low hemostatic effect and inefficiency versus calcified and highly vascularized tumors. CONCLUSIONS: The CO2 laser proved to be a useful and safe tool that could be used for intraventricular pathology; its design is suitable for narrow surgical corridors like interhemispheric fissure and foramen of Monro; its main utility is the ability to create precise and relatively bloodless cut (callosotomy, tumor debulking); low hemostatic effect is its main limit.

A symptomatic large subependymoma with neuroradiological features mimicking a high-grade glioma: A case report.

A subependymoma is a benign primary brain tumor classified as a World Health Organization grade I tumor; it is asymptomatic in most cases. We present the case of a 66-year-old Japanese man with a complaint of recurrent vomiting that led to the discovery of a large mass with hemorrhage, peritumoral edema, and a midline shift in the posterior horn of the right lateral ventricle. The patient was pathologically diagnosed with subependymoma after undergoing total tumor resection; a year after the surgery, he was free from tumor recurrence. Although symptomatic subependymomas are rare, they tend to show hemorrhage with peritumoral edema on neuroradiological tests and tend to be confused with high-grade brain tumors. In the present case, we highlight the importance of the appropriate diagnosis for subependymomas showing neuroradiological features that mimic high-grade gliomas. This diagnosis will help in providing suitable treatment for subependymomas.

Subependymomas - Characteristics of a "Leave me Alone" Lesion. / Subependymome ­ Charakteristika einer "leave me alone"-Läsion.

PURPOSE: Intracranial subependymomas are rare, mostly asymptomatic tumours, which are often found incidentally and therefore did not receive much attention in previous literature. By being classified as benign grade I in the WHO classification of tumours of the central nervous system, they are given a special status compared to the other ependymal tumours. Tumor recurrences are a rarity, spinal "drop metastases" do not occur. While etiological, pathological and therapeutic characteristics have been subject of several publications over the last few decades and have meanwhile been well studied, the imaging characteristics are much less well received. MATERIAL AND METHOD: Retrospective analysis of our relatively large group of 33 patients with subependymoma, including 4 patients with a mixture of subependymomas with ependymal cell fractions in terms of imaging and clinical aspects and with reference to a current literature review. RESULTS: Subependymomas have typical image morphologic characteristics that differentiate them from tumors of other entities, however, the rare subgroup of histopathological mixtures of subependymomas with ependymal cell fractions has no distinctly different imaging properties. CONCLUSIONS: Knowing the imaging characteristics of subpendymoma and their differential diagnoses is of particular importance in order to be able to decide between the necessity of follow-up controls, an early invasive diagnosis or, depending on the entity, tumor resection. KEY POINTS: · Subependymomas have typical imaging characteristics that are clearly distinguishable from other entities.. · Increased incidence in middle/ older aged men, most frequent localization: 4th ventricle.. · Symptomatic subependymomas, often located in lateral ventricles, are usually characterized by hydrocephalus.. · Radiological identification of mixed subependymoma with ependymal cell fractions is not possible.. · Image based differentiation from other entities is important for the procedure.. CITATION FORMAT: · Kammerer S, Mueller-Eschner M, Lauer A et al. Subependymomas - Characteristics of a "Leave me Alone" Lesion. Fortschr Röntgenstr 2018; 190: 955 - 966.

The natural history of subependymal giant cell astrocytomas in tuberous sclerosis complex: a review.

Tuberous sclerosis complex (TSC) is an auto-somal-dominant inherited condition with an incidence of approximately 1:6000 births, characterised by deregulated mTOR activity with multi-site hamartomas. Subependymal giant cell astrocytomas (SEGA) are one such hamartoma, affecting up to 24% of patients with TSC. Their intraventricular location may lead to life-threatening obstructive hydrocephalus. Current management is hampered by a lack of understanding regarding the natural history, behaviour and growth patterns of SEGA. We review the current literature to summarise what is known about SEGA in the following areas: (1) diagnostic criteria, (2) prevalence, (3) origin, (4) imaging characteristics, (5) growth rate, (6) genotype-phenotype correlation, (7) congenital SEGA and (8) SEGA as a marker of severity of other TSC manifestations.

Bilateral lateral ventricular subependymoma with extensive multiplicity presenting with hemorrhage.

This 48-year-old-man who had undergone right thyroid lobectomy for undifferentiated thyroid carcinoma nine years earlier developed generalized seizures. His cerebrospinal fluid was xanthochromic with elevation of total protein. Computed tomography (CT) showed mixed-density bilateral ventricular masses. Magnetic resonance imaging (MRI) revealed multiple nodules in both lateral ventricles; they were heterogeneously enhanced by gadolinium. Diffuse hyperintensity in the right medial temporal lobe and bilateral subependymal area was noted on fluid-attenuated inversion recovery images. Susceptibility-weighted imaging showed low intensity in the masses and cerebellar sulci suggesting hemorrhage and hemosiderin deposition. The preoperative diagnosis was disseminated malignant tumor with recurring hemorrhage. Histological examination of biopsy specimens showed clusters of cells with small uniform nuclei embedded in a dense fibrillary matrix of glial cells and microcystic degeneration. Pseudo-rosettes indicating ependymoma were absent. Microhemorrhages and hemosiderin deposits were noted. Immunohistochemically, the background fibrillary matrix and neoplastic cells were positive for glial fibrillary acidic protein. Mutated isocitrate dehydrogenase-1 was negative. The MIB-1 index was 1.5%. The tumor was pathologically diagnosed as subependymoma containing microhemorrhages and hemosiderin deposits. The extensive multiplicity and hemorrhage encountered in this case have rarely been reported in patients with subependymoma.

Multiple supratentorial subependymomas causing obstructive hydrocephalus.

INTRODUCTION: Subependymomas are benign intraventricular tumours that most often occur asymptomatically and are found incidentally on autopsy. Symptomatic examples requiring surgical intervention are exceedingly rare. CASE PRESENTATION: A 55-year-old man with no history of neurological symptoms presented with multiple episodes of loss of consciousness and increasing headaches. MRI revealed a lobulated intraventricular mass centred at the right Foramen of Monro. Obstructive hydrocephalus with localised midline shift and a second lesion were noted. Right frontal craniotomy with total removal via transcortical resection was performed. DISCUSSION: Symptomatic subependymomas generally present with signs of hydrocephalus due to obstruction of cerebrospinal fluid pathways. There is only one other reported case of multifocal subependymomas in a symptomatic patient. An example of multiple supratentorial subependymomas causing obstructive hydrocephalus has not been previously reported. CONCLUSIONS: Multiple subependymomas are rare. Judicious surgical management with full excision led to symptomatic improvement in our patient.