Endodermal cyst anterior and anterolateral to the brainstem. A report of an experience with seven cases

Surgical Experience and Management of Intracranial Neurenteric Cysts: Single-Center Experience and Review of the Literature

Background: Neurenteric cysts (NEC) are rare, congenital lesions lined by endodermal cell-derived columnar or cuboidal epithelium. Based upon previous studies, gross total removal of the capsule has been presumed to be the ideal surgical goal. Objective: This series was undertaken to further understand the risk of recurrence based on extent of capsule resection. Methods: Records were retrospectively reviewed for all patients with radiographic or pathological evidence of intracranial neurenteric cyst from 1996 to 2021. Results: A total of 8 patients were identified; Four of 8 (50%) presented with headache, four had signs of one or more cranial nerve syndromes. One patient (13%) presented with 3rd nerve palsy, one (13%) had 6th nerve palsy, and two (25%) with hemifacial spasm. One patient (13%) presented with signs of obstructive hydrocephalus. MRI demonstrated T2 hyper- or iso-intense lesions. Diffusion-weighted imaging was negative in all patients (100%) and T1 contrast-enhanced imaging demonstrated minimal rim enhancement in two patients (25%). In 3 of 8 (38%), a gross total resection (GTR) was achieved; while in 4 (50%) a near-total resection, and in one (13%) a decompression was performed. Recurrences occurred in 2 (25%) patients, one with decompression and another with near-total resection, among these ½ required repeat surgery after a mean follow-up of 77 months. Conclusion: In this series, none from GTR group demonstrated recurrence, while 40% of those receiving a less than gross total resection recurred, underpinning the importance of maximally safe resection in these patients. Overall patients did well without major morbidity from surgery.

Pediatric intracranial neurenteric cyst of the oculomotor nerve: a case-based review

BACKGROUND

Neurenteric cysts (NECs) of the central nervous system (CNS) are uncommon congenital entities arising from embryonal elements. Intracranial NECs in the pediatric population are rare.

METHODS

The authors describe the presentation, radiographic imaging, and pathologic findings of an 11-year-old boy with a right oculomotor nerve NEC. A literature review was performed to identify additional cases of pediatric intracranial NECs published in the English language, over the past 30 years (1990-2020). The authors discuss the presentation, investigations, management, and prognosis of this interesting entity.

RESULTS

We describe an 11-year-old boy who presented to neurosurgical attention with disconjugate gaze, anisocoria, and ptosis. Magnetic resonance imaging (MRI) demonstrated a lobulated, cystic, and peripherally enhancing mass involving the right oculomotor nerve. The patient underwent pterional craniotomy for drainage of the cyst and subtotal resection of the cyst wall. The tan-colored mass was displacing the basilar artery, compressing the cerebral peduncle, and adherent to the inferior surface of the tentorium. The lesion was within the oculomotor nerve and splitting the fibers, and the cystic contents were thick and mucinous. Histopathological examination of the specimen demonstrated a thin fibrous cyst wall with scattered inflammatory cells and lined by simple columnar epithelium containing mucin. The lining cells were immunoreactive with epithelial membrane antigen (EMA) and pan-keratin AE1/AE3. The diagnosis of a NEC was rendered. A comprehensive literature review of pediatric intracranial NECs yielded 46 additional lesions published in the literature, involving the skull base, posterior fossa, cerebral convexity, and cranial nerves. NECs present with local mass effect and less commonly, with aseptic meningitis or intracystic hemorrhage. Maximal safe GTR remains the mainstay management, although cyst drainage and marsupialization, cyst shunting, and fenestration of cystic contents into the ventricle or basal cisterns have been reported with variable success.

CONCLUSION

CNS NECs are rare congenital entities; although they occur less frequently in the intracranial components compared to the spine, their diagnosis and management should be considered for intracranial cystic lesions. Maximal safe GTR is the mainstay treatment and frequently yields favorable outcomes.

Endodermal cyst: rare intraaxial brainstem location. Illustrative cases

BACKGROUND

This report detailed an extremely rare location of an endodermal cyst. Such location of the tumor can pose radiological confusion and a therapeutic dilemma. However, when identified, it can be a pleasant surprise for the surgeon and provide the possibility of a symptom-free long life for the patient.

OBSERVATIONS

This report discussed two young patients who presented with relatively short-duration reports of ataxia and diplopia. Investigations revealed intraaxial brainstem lesion. During surgery, thick, pus-like fluid was evacuated and part of a wall was resected. Histology revealed that the lesion was an endodermal cyst. Both patients are well and are lesion- and symptom-free for 24 and 72 months.

LESSONS

Endodermal cysts are some of the few long-standing and benign intraaxial brainstem lesions.

Neurenteric Cyst Masquerading as Acute Flaccid Paralysis in a 2-Month-Old Infant

BACKGROUND

Neurenteric cysts rarely present in infancy. Compressive myelopathy or meningitis are the usual presenting features of these cysts in infants.

CASE DESCRIPTION

We discuss a case of intradural extramedullary neurenteric cyst at the cervicomedullary junction in a 2-month-old infant who presented with features of acute onset flaccid upper limb weakness. The cyst was excised completely and the child improved.

CONCLUSIONS

Although rare, compressive lesions such as neurenteric cysts may present with acute flaccid paralysis in very young children. Differentiating from other causes and timely intervention bears an excellent outcome.

Endodermal Cyst Arising from the Oculomotor Nerve: A Case Report Outlining the Novel Insertion of Cysto-subarachnoid Shunt for Refractory Disease

BACKGROUND

Endodermal cysts of the oculomotor nerve are rare presentations. Only case reports are available to help guide clinicians with managing this rare entity.

CASE DESCRIPTION

A 3-year-old boy presented with an acute on chronic left oculomotor nerve palsy due to a left interpeduncular cistern cyst found on magnetic resonance imaging. He underwent a left pterional craniotomy and fenestration of the histologically proven endodermal cyst and had initial improvement at the 2-month review. He subsequently developed clinical and radiologic evidence of recurrence and was treated surgically with a refenestration and insertion of a cysto-subarachnoid shunt through a trans-sylvian approach. At 6-month follow-up, there was complete resolution of the oculomotor nerve palsy with interval development of oculomotor synkinesis.

CONCLUSIONS

Magnetic resonance imaging is an essential modality in the follow-up of these patients postoperatively in the setting of unchanged or deteriorated neurology. Fenestration of the cyst is appropriate first-line surgical management; however, a cysto-subarachnoid shunt is a safe consideration in recurrent, symptomatic cysts and provides sustained symptom resolution.

A unique finding of cavum velum interpositum colloid-like cyst and literature review of a commonplace lesion in an uncommon place

Colloid cysts typically reside within the area of the anterior third ventricle, in the proximity of the foramen of Monro. Although they are considered to commonly localize in various parts of the cerebrum, they are exceedingly rare outside the ventricular system and rarely occur within the velum interpositum. We have reported here a rare case of a velum interpositum colloid-like cyst in a 23-year-old man, who presented to our clinic with temporary binocular strabismus, which he had been experiencing for the previous year. In addition, we have briefly reviewed evidence regarding the generation, anatomy, and pathogenesis of colloid cysts, as well as the management options for such rare cases. The present report is only the third to describe a colloid-like cyst located within the velum interpositum, providing additional data that may aid in elucidating the pathogenesis of these neoplasms.

Single-Center Clinical Characteristics and Treatment Experience of Foramen Magnum Neurenteric Cyst: Report of 6 Cases and Brief Review of the Literature

OBJECTIVE

To retrospectively analyze the clinical data of 6 patients with foramen magnum (FM) neurenteric (NE) cysts, and summarize the clinical characteristics and treatment experience for this rare disease in our single center.

METHODS

Between January 2011 and December 2015, 6 patients with FM NE cyst were surgically treated at Xuan Wu Hospital of Capital Medical University. We summarize the treatment experience of these patients through a retrospective review of the clinical information, imaging features, surgical details, and follow-up outcomes.

RESULTS

All 6 patients were female, ranging in age from 15 to 54 years (mean age, 36.8 ± 12.9 years). Occipital headache along with cranial nerve injury were the most common symptoms. Preoperative brain magnetic resonance imaging identified all lesions in the FM region, with an oblong or lobulated shape. The surgical approach was far lateral in 4 patients and suboccipital midline in 2 patients. Total lesion removal was completed in 4 patients, and subtotal excision was performed in the other 2 patients, in whom the cyst wall was intensely adherent to surrounding structures. In all 6 patients, the preoperative symptoms were significantly relieved after surgery. No recurrence was seen after a mean follow-up of 27.3 months (range, 3-70 months).

CONCLUSIONS

Our present study identified a female predominance among patients with intracranial FM NE cyst. Surgical excision is the optimum treatment strategy for this rare disease. Our findings indicate that subtotal removal of an FM NE cyst may be associated with favorable outcomes, but strict long-term follow up is needed.

Endodermal cyst in pineal region: Rare location

Background:

Pineal tumors are very uncommon intracranial lesions, and endodermal cysts in this location are extremely rare.

Case Description:

A 49-year-old right-handed female presented with 3 weeks history of progressive dizziness and imbalance. Imaging studies showed 1.8 cm × 1.7 cm × 1.8 cm pineal lesion with small enhancing mural component displacing ventrally the quadrigeminal plate and narrowing of aqueduct of Sylvius without hydrocephalus. In addition, she was found with small interhemispheric lipoma, and small posterior falx possible meningioma. Cerebrospinal fluid markers obtained by lumbar puncture were all negative. She underwent tumor resection, and final pathology reported endodermal cyst. No new deficits were encountered, and her gait imbalance improved significantly by 3 months follow-up.

Conclusions:

With evidence of enlargement or symptomatic pineal lesions, surgical consideration is necessary. Among pineal lesions, endodermal cysts are extremely uncommon and although benign pathology, long-term follow-up is advised due to unknown chronic behavior.

Ventral foramen magnum neurenteric cysts: a case series and review of literature

Neurenteric cysts (NEC) are uncommon, benign, congenital lesions. Ventral foramen magnum (FM) location is very rare. The difficulties in diagnosis and management aspects are detailed with a review of the pertinent literature. We report four new cases of ventral FM NEC, all managed surgically and present a literature review of ventral FM NEC. A retrospective analysis of histopathologically confirmed cases of ventral FM NEC, operated from 2010-2013 at our institute, was performed. For review, only those cases of NEC extending from the lower clivus to the C2 level constituting the foramen magnum were included. Including our four cases, a total of 47 cases were identified. The male to female ratio was 1.2:1. Mean age was 33.5 years (range 1-60 years). Neck pain and occipital headache were the most common symptoms, followed by limb weakness and cranial nerve paresis. Recurrent meningitis was noted in three cases. Hyperintensity on both T1- and T2-weighted sequences with absent enhancement was the most common finding on MRI. Surgical approaches were as follows: suboccipital (n = 21), far/extreme lateral (n = 18), retrosigmoid (n = 6), and transoral (n = 4). The extent of resection was as follows: total, 26; near total, 6; subtotal, 9; and partial, 3 cases. Cerebrospinal fluid diversion was done in four cases for intracranial hypertension. Mean follow-up duration was 26.8 months (range 1 month-9 years). Recurrence was noted in four (8.5 %) cases. One (2 %) case had malignant transformation. Mortality rate was 4 %. Foramen magnum neurenteric cysts are rare, benign tumors of the central nervous system. Accurate preoperative diagnosis can often be established with MRI. Surgical removal is the treatment of choice. Complete excision is ideal but often not possible. Near total removal would suffice with good progression-free periods. A long-term follow-up with radiological studies is necessary as delayed recurrences can occur.

Cerebellar Enterogenous Cyst with Atypical Appearance and Pathological Findings

BACKGROUND

Intracranial enterogenous cysts are rare and occur mainly in the posterior fossa. These cysts are usually extra-axial, midline, anterior to the brainstem, or at the cerebellopontine angle. Intracranial intra-axial enterogenous cysts are extremely rare. We report a case of an intra-axial cerebellar enterogenous cyst in which diagnosis was difficult because the lesion resembled an arachnoid cyst in appearance and showed atypical pathologic findings.

CASE DESCRIPTION

A 69-year-old woman had a 2-year history of progressive headache, giddiness, and unsteadiness of gait. Magnetic resonance imaging showed a cystic lesion with isointensity to cerebrospinal fluid in the left cerebellar hemisphere, reaching into the fourth ventricle. The patient underwent fenestration of the cyst and creation of a communication between the fourth ventricle and cyst because the tight attachment of the cyst wall to the cerebellum prevented total removal of the cyst. Although pathologic examinations did not show findings typical of enterogenous cyst, the diagnosis was finally made based on the presence of basement membrane and immunohistochemical results.

CONCLUSION

The diagnosis of enterogenous cyst is based mainly on histologic findings, because characteristic findings on neuroimaging have not been defined. Although total resection of enterogenous cysts is recommended in general, partial resection while ensuring the cyst communicates adequately with the surrounding cerebrospinal fluid space with or without a shunt procedure may be useful if the cyst is adherent to surrounding neurovascular structures.

Rare location of a colloid cyst - case presentation

Not only pituitary adenomas, but also a number of tumors may arise from within the sella presenting a diagnostic and therapeutic challenge at a multidisciplinary specialist level. This article presents a case of a colloid cyst located in sellar region, with overlapping symptoms of a nonfunctioning pituitary adenoma.

Staged bilateral far-lateral approach for bilateral cervicomedullary junction neurenteric cysts in a 10-year-old girl

Neurenteric cysts are rare and benign lesions that consist of ectopic alimentary tissue residing in the central nervous system. They tend to occur most frequently in an intraspinal rather than intracranial location. Intracranial neurenteric cysts are a rare occurrence in the pediatric population. These lesions typically present as unilateral cystic structures in the lower cerebellopontine angle and craniocervical junction. To the authors' knowledge, there have been no reported cases of bilateral localization of intracranial neurenteric cysts. In this report, they present an unusual case of a 10-year-old girl who was found to have bilateral intracranial neurenteric cysts at the pontomedullary junction. The patient was successfully treated with staged, bilateral far-lateral transcondylar resection of the cysts. The authors also provide a brief overview of the literature describing intracranial neurenteric cysts in children.

Endoscopic transsphenoidal, transclival resection of an enterogenous cyst located ventral to the brainstem: case report

BACKGROUND AND IMPORTANCE

Enterogenous cysts are rare tumors found most commonly in the spine, but they have also been reported intracranially. Cases of enterogenous cysts located within the posterior fossa have traditionally been resected via difficult craniotomies that require prolonged retraction and risk injury to cranial nerves. We describe a method for resection of an enterogenous cyst located anterior to the brainstem via the endoscopic transsphenoidal approach.

CLINICAL PRESENTATION

A 37-year-old man was found to have a 2-cm mass anterior to the brainstem during routine screening after a trauma. The mass was located within the prepontine cistern, enhanced with gadolinium contrast, and showed no restrictive diffusion. This lesion was most consistent with an enterogenous cyst. A minimally invasive endoscopic endonasal transsphenoidal transclival approach was performed for gross total resection of the tumor.

CONCLUSION

We discuss the endoscopic transsphenoidal approach used for the resection of an enterogenous cyst in the posterior fossa anterior to the brainstem. The transsphenoidal approach provides direct access to lesions in this location using a minimally invasive technique while avoiding excessive brain retraction or injury to cranial nerves. In addition, we provide an updated review of the literature for enterogenous cysts located within the posterior fossa.

MUCINOUS LOW-GRADE ADENOCARCINOMA ARISING IN AN INTRACRANIAL ENTEROGENOUS CYST

OBJECTIVE

Enterogenous cysts (ECs) of the central nervous system are developmental malformations that occur in the spinal canal, posterior fossa, or cerebral hemispheres. They are usually benign lesions, and malignant transformation is rare. To date, only three cases of malignant transformation have been reported in the literature. We present a case of a cerebellopontine EC showing foci of epithelial dysplasia and malignant transformation into a low-grade papillary mucinous adenocarcinoma.

CLINICAL PRESENTATION

A 25 year-old man with a 6-year history of hypoacusia presented to our department with facial nerve deficit, visual disturbances, and gait instability. A magnetic resonance imaging scan demonstrated a multiloculated cerebellopontine angle cyst with supratentorial hydrocephalus.

INTERVENTION

A retrosigmoidal approach was used to achieve cyst removal. This was followed several months later by ventriculoperitoneal shunt placement. The cyst was adherent to the brainstem, cranial nerves, and vessels, and it resembled a thin encapsulated structure filled with mucinous-like substance. No solid component was identified. Histopathological examination revealed an EC with foci of malignant transformation in a mucinous papillary adenocarcinoma. Magnetic resonance imaging was performed 5 months postoperatively due to progressive clinical worsening; this scan revealed lesion recurrence with severe brainstem compression. Emergency surgery was performed, and a large decompression was achieved. Subsequent follow-up computed tomographic scans showed progression of the residual tumor. The patient's neurological condition rapidly worsened, ultimately resulting in death.

CONCLUSION

The present report suggests that a careful histological examination of all ECs after surgery should be made to exclude dysplastic foci or carcinomatous transformation. Although the clinical behavior of ECs with malignant trasformation is unpredictable, surgery remains the treatment of choice. The use of possible adjuvant chemo- or radiotherapy has not been established.

Endodermal cyst of the cranio-cervical junction

We reviewed 36 patients with endodermal cysts occurring at the craniocervical junction. They were aged between 3 and 66 years. Headache, motor weakness, and neck pain were commonly observed symptoms. Radiographically, T1-weighted magnetic resonance imaging of the tumours demonstrated a hypointense, isointense, or hyperintense signal according to the cystic content. In most cases, the cyst walls did not enhance after gadolinium administration. Histologically, the cysts were found to be lined by a single layer of epithelium. Histochemical and immunohistochemical studies showed that almost all were reactive to periodic acid schiff stain, epithelial membrane antigen, and carcino-embryonic antigen, but negative to glial fibrillary acidic protein. Mainly, the suboccipital approach with or without a laminectomy, or the trans-oral approach were selected for surgical excision of these tumours. In 17 of the 36 patients, total or gross total resections were performed, and subtotal resections were achieved in sixteen. Three patients developed recurrences.