Intracranial intraparenchymal and intraventricular schwannomas: Report of 18 cases

Frontal lobe intra-axial schwannoma harboring a CHD7::VGLL3 fusion and heterozygous TSC2 p.F1510del mutation in a young child

BACKGROUND

Brain intraparenchymal schwannoma is a rare clinical entity, generally curable with adequate resection.

METHODS AND RESULTS

We describe a case in a male patient first presenting at 19 months of age, the youngest reported age for this lesion. It also appears to be the first case connected to a germline TSC2 p.1510del mutation in a patient with autism-like symptoms. Although tuberous sclerosis is generally not associated with increased risk of schwannoma, mTORC1 activity, which is inhibited by intact TSC1/TSC2 complex, is involved in schwannoma progression. This patient's tumor also harbored a CHD7::VGLL3 fusion consistent with its genomic DNA methylation classification of CNS Schwannoma, VGLL-fused. The Hippo pathway, mTORC1, and VGLL3 all negatively regulate the YAP1/TEAD cotranscriptional complex. We hypothesize that this schwannoma may have arisen because of increased VGLL3 functional activity from the CHD7::VGLL3 fusion and, perhaps, increased mTORC1 activity due to TSC2 mutation, and their combined effects on the balance between YAP1/TEAD- and VGLL3/TEAD-mediated transcriptional programs.

CONCLUSIONS

We present a frontal lobe intra-axial parenchymal schwannoma containing a CHD7::VGLL3 gene fusion presenting in a 19 month-old male, the youngest patient yet reported for this lesion.

Surgical management of a large cystic trochlear nerve schwannoma mimicking a brainstem glioma: a case report

Introduction

Intracranial schwannomas represent a rare group of intracranial tumors, with purely motor nerve schwannomas being the rarest of them. The anatomical proximity of these tumors to the brainstem may present a radiological challenge in differentiating them from intra-axial brainstem tumors, which can influence further decision-making and treatment options.

Methods

We report on a 47-year-old male patient who was diagnosed with a large cystic intracranial tumor with radiological features suggestive of an intrinsic brainstem glioma.

Results

After discussing treatment options and risks based on a presumed radiological diagnosis, microsurgical treatment via lateral-suboccipital craniotomy in semi-sitting position, under continuous intraoperative neuromonitoring was performed. Intraoperative findings proved that the tumor was an extra-axial schwannoma originating from the left trochlear nerve. Gross total removal of the lesion was achieved.

Conclusion

Due to their rarity, non-specific symptoms and the possibility to mimicking intra-axial brainstem tumors on imaging, these tumors may present a diagnostic challenge and should be taken into account during treatment decision-making.

Intraventricular schwannomas: A case report and a literature review

Intraventricular schwannomas are extremely rare, typically benign tumors originating from Schwann cells, which are not normally found within the ventricular system. Their presence challenges conventional understanding of tumor origins and complicates diagnosis and management. We report the case of a 19-year-old female presenting with a drop attack and headache, with no significant medical history. MRI revealed a heterogeneously enhancing lesion in the right lateral ventricle. Differential diagnoses included malignant tumors; however, histopathological examination post-surgical resection confirmed an intraventricular schwannoma. Postoperative outcomes were favorable, with successful CSF diversion via a right occipital ventriculoperitoneal shunt for isolated right temporal hydrocephalus. This case is notable for its atypical presentation in a young patient, challenging the conventional understanding that intraventricular schwannomas primarily affect older individuals. In addition, the correct diagnosis and successful management of a rare intraventricular schwannoma underscores the importance of considering this rare diagnosis in patients with nonspecific neurological symptoms and intraventricular lesions. This case, alongside the literature review, enriches the body of evidence on intraventricular schwannomas, highlighting the critical role of surgical intervention and the need for a comprehensive diagnostic approach.

Lateral ventricle ectopic schwannoma: Case report and literature review

Background

Cases of lateral ventricular ectopic schwannomas (LVES) are extremely rare, with only 23 cases reported thus far. This study aimed to obtain a better understanding of the disease.

Methods

We reported a rare case of LVES, in which the patient was admitted to our hospital, and reviewed the relevant literature on LVES to summarize and analyze the clinical manifestations, pathologies, imaging features and progress.

Results

Of the 23 patients, LVES was more common in men (74%, 17/23) than in women and was mostly located on the right side (78%, 18/23). The average age at clinical presentation was 28 years, with an age range between 8 and 68 years. Moreover, most cases were histologically benign, except in one case of malignancy. In all the benign cases, there were 2 cases of subtotal resection, but no recurrence was found during follow-up.

Conclusions

The origin of LVES could be the tumor transformation of autonomic nerve tissue in the perivascular choroid plexus. For lateral ventricle tumors,which are rare benign lesions with good prognosis after surgical resection, LVES should be considered in the differential diagnosis. Moreover, whether LVES could be considered for gamma knife treatment, similar to a small acoustic neuromas,requires further investigation.

CT and MRI findings of intra-parenchymal and intra-ventricular schwannoma: a series of seven cases

Objective

To analyze the computed tomography (CT) and magnetic resonance imaging (MRI) features of patients with intra-parenchymal and intra-ventricular schwannoma.

Methods

The CT and MRI features of seven cases with intra-parenchymal and intra-ventricular schwannoma were analyzed retrospectively.

Results

There were four men and three women (median age, 25 years; range, 12–42 years) in this study. The median tumor size was 4.4 cm (range, 3.1–6.5 cm). The mass was, respectively, round in four cases (57.1%), lobulated in two cases (28.6%) and oval in one case (14.3%). All tumors were well-circumscribed. Septa in the mass could be observed in three cases (42.9%), and nodular calcification was observed in two cases (28.6%), which peritumoral edema (n = 3, 42.9%) and hydrocephalus (n = 3, 42.9%) could be observed. Most of these lesions (n = 6) presented iso-hypointensity on T1-weighted images and iso-hyperintensity on T2-weighted images, except one lesion showing low intensity on T2WI. In addition, a fluid–fluid level was observed in one case. After contrast agents’ injection, all masses illustrated heterogeneously moderate to marked enhancement.

Conclusions

A well-defined solid and cystic mass with calcification and moderate to marked delayed enhancement may be an objective account of intra-parenchymal or intra-ventricular schwannoma.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12880-022-00917-z.

Ectopic schwannoma of the sellar region in a 1-year-old child: A case report and review of literature

Background:

Schwannomas are cranial and spinal nerves’ sheath tumors accounting for up to 8% of all intracranial neoplasms. Although typical intracranial schwannomas originate from Schwann cells surrounding cranial nerves, ectopic schwannomas are not associated with a known cranial nerve or have an unknown origin. The location of schwannomas may impose clinical challenges. Sellar region schwannomas are rare whether it is ectopic or not. Herein, we report a pediatric case of a 1-year-old female with ectopic, intra-supra sellar with a literature review. We report the first case of juvenile ectopic schwannoma in the sellar region.

Methods:

A PubMed Medline database search was performed by the following combined formula of medical subject headings (MESH) terms and keywords: ((sella turcica [MeSH Terms]) OR (sella*[Title/Abstract]) OR (ectopic [Title/Abstract]) AND ((neurilemmoma [MeSH Terms]) OR (schwannoma [Title/Abstract]) OR (neuroma [Title/Abstract]) OR (neurinoma [Title/Abstract])).

Results:

Total results of 206 articles were obtained. In exclusion of intraparenchymal and intraventricular schwannomas, only 34 articles remained. Thirty-nine cases were included in 34 articles. According to the reported cases, intrasellar schwannomas are more common in elderly individuals in an average of 49.5 years (range: 19– 79 years). They have a good prognosis and affect males to females equally (20:19).

Conclusion:

Ectopic schwannoma sited in the sellar region is rare. It is the first case to be reported in the pediatric age group with a literature review. This lesion should be highlighted and included in the differential diagnosis of sellar mass.

An Unsuspected Intraventricular Schwannoma

Intraventricular schwannomas are rarely encountered in neurosurgical practice. The development and progression of a schwannoma within the ventricular system is still a hypothesised theory. Here, we present a case of a 59-year-old female who presented with a three-week history of headaches. Her symptoms progressively worsened, with resultant altered mental status within the last week. Imaging scans of the brain demonstrated a well-defined mass within the right lateral ventricle with associated midline shift and obstructive hydrocephalus. A parietal craniotomy and resection of the intraventricular mass was performed. Her postoperative course was uneventful. Histopathological assessment depicted a biphasic pattern of Antoni A and B, with a strongly positive S100. This was in keeping with an intraventricular schwannoma. The diagnosis of an intraventricular schwannoma does not fit within the classical differential framework for ventricular masses. These tumours are extremely uncommon but fortunately, they are typically benign. Therefore, adequate surgical resection remains the gold standard of care for these unfamiliar masses.

Brainstem intraparenchymal schwannoma: A case report and literature review

Background:

Intracranial intraparenchymal schwannomas (IS) are rare tumors that have mainly been described in case reports. Here, we report on a case of a brainstem IS and included a comprehensive literature review.

Case Description:

A 74-year-old man presented with progressive gait disturbances. CT- and MRI-imaging revealed a contrast-enhancing mass accompanied by a cyst in the dorsolateral pons. Hemangioblastoma was suspected and surgery was advised. During surgery, gross total resection of a non-invasive tumor was performed. Postoperative recovery was uneventful. Based on histopathological examination, the intraparenchymal brainstem tumor was diagnosed as schwannoma.

Conclusion:

Our extensive review illustrates that ISs are benign tumors that most often present in relatively young patients. Malignant cases have been described but form an extremely rare entity. Preoperative diagnosis based on radiological features is difficult but should be considered when peritumoral edema, calcifications, and cysts are noted. In benign cases, gross total resection of the lesion is curative. To adequately select this treatment and adjust the surgical strategy accordingly, it is important to include IS in the preoperative differential diagnosis when the abovementioned radiological features are present.

Intraparenchymal Schwannoma: A Rare Entity

A 60-year-old woman noted headaches, transient visual obscurations and pulsatile tinnitus. She had Frisén grade 4 papilloedema. Brain magnetic resonance imaging showed a large subfrontal cystic mass with ring enhancement. Tumour pathology was in-keeping with an intraparenchymal schwannoma. This uniquely rare tumour is discussed.

Fractionated Radiosurgical Treatment of Intracerebral Schwannoma: A Case Report and Literature Review

Intracranial schwannomas (ICS) unrelated to the cranial nerves are extremely rare; around 70 cases have been reported worldwide. The available literature consists of case reports and small series that present variable characteristics distinguishing these lesions. Brain parenchyma schwannomas are typically benign tumors with currently unknown origins. Diagnosis of intraparenchymal schwannoma is almost never made preoperatively. The management of these tumors usually consists of gross total resection, chemotherapy, and radiotherapy in cases of recurrence. The authors present a case of fractionated Gamma Knife radiosurgical treatment of intracerebral schwannoma following partial microsurgical resection.

Diagnosis of a Rare Intraventricular Schwannoma

BACKGROUND

Intraventricular schwannoma is extremely rare, with only 35 cases reported to date in the literature. Consequently, its etiology and pathogenesis are still unclear, and therefore require further investigations. Here, we report on and discuss a rare case of intraventricular schwannoma to elucidate on this matter.

CASE DESCRIPTION

A 26-year-old man was admitted to our institution with a 1-month history of headaches and left hemianopsia. At diagnosis, magnetic resonance imaging of the brain revealed a well-demarcated mass with surrounding edema in the right lateral ventricle. Total resection of the tumor was performed by a transsulcal approach through the right parietal lobe. In surgery, it was observed that the tumor was attached to the choroid plexus without invading the wall of the right lateral ventricle. The respective histologic examination confirmed the diagnosis of intraventricular schwannoma. Six months after the surgery, there was no recurrence. Additionally, during this follow-up period, the patient did not develop any neurologic deficit, including visual field narrowing or parietal symptoms, such as acalculia and right-left, finger, and space agnosias.

CONCLUSIONS

Although intraventricular schwannomas are rare, 35 cases have already been reported to date. We emphasize the importance of diagnosing such cases correctly to increase knowledge on the origin and pathogenesis of intraventricular tumors, which would facilitate disease management.

Frontal lobe intracerebral schwannoma mimicking metastatic lesion in a patient with papillary thyroid carcinoma

Intracerebral schwannomas are quite rare. Due to their rarity and lack of pathognomonic imaging features, intracerebral schwannoma may be overlooked in the initial differential diagnosis of an intra-axial mass with heterogeneous ring enhancement, such as a high-grade glioma, metastasis or lymphoma. Here, we present a 21-year-old woman with prior diagnosis of papillary thyroid carcinoma and recent history of seizures who had a heterogeneously ring-enhancing left frontal lobe mass. Our presumptive diagnosis was a metastatic tumor since she had a history of thyroid cancer. Because of uncertainty in preoperative differential diagnosis, the decision was made to proceed with excisional biopsy of the tumor via craniotomy. She underwent uneventful gross total resection of the tumor that histopathology revealed as an intracerebral schwannoma.

Intraventricular schwannoma: Case report and review of literature

We report here a case of intraventricular schwannoma. This location is rare. Our patient was a 68-year-old female with a large intraventricular lesion of the body of the lateral ventricle on the right side. Brain magnetic resonance imaging (MRI) revealed this lesion. After a right parietotemporal craniotomy, microsurgical excision using neuronavigation was performed to completely remove the tumor. Histological and immunohistochemical examination confirmed the diagnosis of intraventricular schwannoma devoid of atypical features. Postoperative MRI showed macroscopically complete tumor removal with no recurrence after 12 months of follow-up. A review of the literature identified 32 such cases published to date.

Case report of intraventricular schwannoma

We describe the case of a 52 year old male presenting with subacute headache. Cranial imaging suggested haemorrhage into a parietal, partially intraventricular, space occupying lesion. The radiology was interpreted to be most consistent with a glioblastoma. The lesion was near totally resected. The histopathology was a WHO grade 1 schwannoma.

Supra and infratentorial ectopic schwannoma mimicking a meningioma

We report the case of a supra and infratentorial ectopic schwannoma, mimicking a meningioma, that was surgically resected on a 75-year-old man, with a history of progressive visual loss and headaches. MRI was in favour of an occipital, cystic, tentorial-based meningioma extending to the posterior fossa, with signs of intratumoral haemorrhage. This is a unique case because of the rare type of lesion, in a very atypical location, completely unexpected by the preoperative imaging analysis, and to the best of our knowledge it is the oldest patient reported in the literature with this kind of tumour.

Intraventricular Neurilemmoma (Schwannoma): Shall GFAP Immunostaining Be Regarded as a Histogenetical Tag or as a Mere Histomimetical Trait?

Neurilemmomas are benign neoplasms presumedly derived from Schwann cells which rarely originate within the central nervous system. Moreover, their intraventricular location has been seldom noticed with less than 30 cases reported worldwide. Here, we add another case study to the record as well as the fifth one in Latin American population. A 16-year-old boy without significant past clinical data debuted with headache and progressive left eye blindness during six months. Neuroimaging scans showed a bulky, multiloculated, intraventricular tumour emerging from the posterior horn of the left lateral ventricle. Microscopically, the lesion put on view the classical schwannian histology: spindle cells arranged in both compact and loosely textured areas. Verocay bodies were not present but vessel hyalinisation, pericellular reticulin, and senescent atypia were observed. The immunoperoxidase reactions were also consistent with neurilemmal differentiation; however, glial fibrillary acidic protein expression was widespread and unexpectedly seen. Traditionally conceived as “nerve sheath tumours” the dual immunophenotype herein demonstrated points to a different histogenetical pathway other than sheer Schwann cell derivation. As previously advised by some authors, neoplastic transformation from a multipotent stem cell may explain the occasional finding of these tumours in unconventional intracranial compartments.

An Intraventricular Schwannoma with Associated Hydrocephalus and Ventricular Entrapment: A Case Report

Intraventricular schwannomas are rare primary brain tumors, with fewer than 25 cases reported in the literature. Here, we present the case of a 20-year-old male patient with a 2 year history of blurry vision and dysesthesia involving his right occiput and upper neck. Imaging demonstrated a homogeneously enhancing mass located within the atrium of the right lateral ventricle with associated right lateral ventricular entrapment. Pathology confirmed the tumor to be an intraventricular schwannoma. Imaging findings, presentation, complications, and treatment options for intraventricular schwannomas are described.

An atypical case of intracerebral schwannoma

We report a case of intracerebral cystic schwannoma in the temporal fossa manifested as a gradually worsening headache in a 49-years-old woman. Computed Tomography (CT) and magnetic resonance imaging (MRI) showed a left temporal partly cystic, partly solid mass. The preoperative diagnosis was astrocytoma or glioblastoma multiforme (GBM), but microscopic examination of the mass showed the characteristic pattern with cellular Antony A component. Immunohistochemically, the tumor was positive for S-100 protein. These findings are consistent with a schwannoma. Intracerebral schwannomas not related to cranial nerves are rare and most reported cases involved young patients.

Intracerebral schwannoma mimicking meningioma: case report

Intracranial schwannomas account for 8% of all primary brain tumors, approximately 80-90% of them being seen in the cerebellopontine angle in relation to the vestibular nerve. Schwannomas arising within brain parenchyma, unrelated to the cranial nerves, are extremely rare. To our knowledge, only 73 cases of intracerebral schwannoma have been described in the English-language literature so far,1-5 but only six cases of intracerebral schwannoma mimicking meningioma have been reported1-3 and there have been few reports regarding neuroradiological findings. Disagreement remains concerning the histogenesis of these tumors.

Supratentorial brain schwannomas: an uncommon location for a common tumour

INTRODUCTION

Intracranial schwannomas not related to cranial nerves are uncommon brain tumours. Such tumours account for less than 1% of all surgically treated schwannomas. Only 79 cases have been reported in the literature.

METHODS

We describe two cases treated in our centre. The patients are young women with seizures as a presenting symptom. Both underwent surgery with the presumptive diagnosis of benign brain tumour. Histopathological examination revealed the certain diagnosis of Schwannoma.

RESULTS

Good outcome was achieved with total excision of the tumour. Based on the literature, demographic data, clinical aspects, imaging features and theories on the possible origin of this rare tumour are discussed.

CONCLUSIONS

These tumours should be included in the differential diagnosis of supratentorial benign tumours in young adults. Total excision, whenever possible, is the treatment of choice.