Intracranial neuroenteric cysts: A concise review including an illustrative patient

A ventral brainstem neurenteric cyst - A case report and review of the pre-brainstem location

Background

Neurenteric cysts are uncommon, benign endoderm-derived lesions that result from aberrant embryologic development of the notochord. They are typically located in the intradural extramedullary spinal cord and rarely located intracranially. Contrary to spinal-located cysts, intracranial cysts are rarer in the pediatric population. Clinically, they may present with symptoms of mass effect, or they can be incidentally discovered.

Case Description

A 10-year-old healthy female child presented with recurrent headaches. The physical and neurological examination was unremarkable. Brain magnetic resonance imaging (MRI) showed a well-demarcated lesion anterior to the pontomedullary junction with striking T1 and T2/T2 fluid-attenuated inversion recovery high-signal intensity and a small rounded nodule within of low signal on T1, T2, and T2*. On initial conservative strategy with serial brain MRI, there was a progressive enlargement of the lesion with significant mass effect on the brainstem. The patient underwent a right retrosigmoid craniotomy, and the cyst wall was fenestrated and drained. Part of the cyst wall and the solid nodule were adherent to the brainstem and basilar artery and were not removed. The histologic findings were consistent with the diagnosis of a benign endodermal cyst. The postoperative period was uneventful.

Conclusion

We report a successful surgical treatment of this rare congenital cyst located in the ventral brainstem. We present pre-and post-operative imaging findings, intraoperative microscopic images of the procedure, and a brief review of relevant clinical literature on the topic.

Enigmatic echoes: Exploring brainstem neurenteric cysts - A case series and literature review

INTRODUCTION AND IMPORTANCE

Neurenteric cysts (NCs) are rare congenital anomalies within the central nervous system, originating from the endodermal layer due to inappropriate embryonic notochordal plate and endoderm separation. Despite constituting a minute fraction of CNS tumors, their diverse clinical presentations and brainstem occurrence pose diagnostic challenges.

CASE PRESENTATION

This study presents a series of three brainstem NCs, detailing demographics, clinical presentations, radiological features, and operative findings. Patients aged 2-40 years exhibited varied symptoms including headaches, vomiting, cranial nerve deficits, and motor/sensory deficits. Literature review of 27 cases showed a mean age of 26.8 years, predominantly in females, with diverse cystic characteristics on MRI. Surgical intervention achieved mostly complete resection, with varying outcomes including recurrence and malignant transformation.

CLINICAL DISCUSSION

This study sheds light on the rare entity of brainstem NCs, emphasizing their diagnostic complexity. NCs, though constituting a minute fraction of CNS tumors, present a diagnostic challenge due to their diverse clinical presentations and rarity in the brainstem.

CONCLUSION

This study provides insights into brainstem NCs, emphasizing diagnostic complexity and the importance of MRI in accurate diagnosis and surgical intervention. Enhanced collaboration is needed to refine management strategies for these intriguing lesions.

Follicular carcinoma of the thyroid presenting as metastasis in the wall of an arachnoid cyst

The brain is an uncommon site for metastases of differentiated thyroid carcinoma with the most common location being cerebral hemispheres, followed by cerebellum and pituitary gland. Metastasis in the wall of an arachnoid cyst is exceedingly rare with single case report available in the published literature. Arachnoid cyst metastasis from an extraneuraxial malignancy has not been published until. We present a unique case of thyroid carcinoma metastasizing to the wall of an intracranial arachnoid cyst and the most interesting fact is that it was the first clinical manifestation of her malignancy.

Imaging of congenital and developmental cystic lesions of the brain: a narrative review

INTRODUCTION

Congenital and developmental intracranial cysts represent a large heterogenous group with varied presentations and etiologies. They can range from normal variants to pathologic lesions often associated with known congenital syndromes or acquired insults. While some are incidentally found, others are symptomatic or may become symptomatic over time. The preferred type of neuroimaging for timely diagnosis helps determine appropriate management and treatment, if indicated.

AREAS COVERED

In this narrative review article, authors present a comprehensive description of developmental cystic lesions. Imaging descriptions are provided for each type of cystic lesion as well as several representative images.

EXPERT OPINION

As advanced neuroimaging techniques become more ubiquitous in clinical use, more light may be shed on the natural history of certain intracranial cystic lesions throughout the lifespan. This includes prenatal imaging for early identification and prognostication to surveillance imaging into advanced age to ascertain associations of certain cystic lesions with age-related cognitive dysfunction.

Incidental findings on brain magnetic resonance imaging (MRI) in adults: a review of imaging spectrum, clinical significance, and management

Utilization of brain MRI has dramatically increased in recent decades due to rapid advancement in imaging technology and improving accessibility. As a result, radiologists increasingly encounter findings incidentally discovered on brain MRIs which are performed for unrelated indications. Some of these findings are clinically significant, necessitating further investigation or treatment and resulting in increased costs to healthcare systems as well as increased patient anxiety. Moreover, management of these incidental findings poses a significant challenge for referring physicians. Therefore, it is important for interpreting radiologists to know the prevalence, clinical consequences, and appropriate management of these findings. There is a wide spectrum of incidental findings on brain MRI such as asymptomatic brain infarct, age-related white matter changes, microhemorrhages, intracranial tumors, intracranial cystic lesions, and anatomic variants. This article provides a narrative review of important incidental findings encountered on brain MRI in adults with a focus on prevalence, clinical implications, and recommendations on management of these findings based on current available data.

Meningeal carcinomatosis secondary to neurenteric cysts with malignant transformation: a case report

Background

Meningeal carcinomatosis is mainly associated with breast cancer, lung cancer, and melanoma. However, meningeal carcinomatosis secondary to a neurenteric cyst with malignant features is extremely rare.

Case presentation

We report the case of a 35-year-old woman who was admitted to the hospital with a 10-month history of headache, 6-month history of diplopia, 4-month history of hearing loss, and 1-month history of back pain, suggesting a diagnosis of chronic meningitis. Notably, enhanced brain and spinal cord magnetic resonance imaging (MRI) revealed extensive lesions with enhancement signals in the pia mater of the pons and cervical, thoracic, and lumbar spinal cord. The cerebral spinal fluid profile showed that pressure was significantly elevated, with a slight increase in leukocytes that mostly comprised mononuclear cells and decreased glucose concentration. Cytology evaluation showed a small cluster of atypical nuclei, which were suspected to be tumor cells arising from the epithelium. However, no primary tumor was found through comprehensive body and skin screening. After a histopathological biopsy of subarachnoid meninx of the thoracic spinal canal, the cause of meningeal carcinomatosis of this patient was determined as neurenteric cysts with malignant features, which is extremely rare.

Conclusion

This is the first case to ever report neurenteric cysts as a cause of leptomeningeal carcinomatosis and the first ever report of neurenteric cysts presenting as leptomeningeal carcinomatosis without typical cyst visible on brain MRI. This extremely rare case provided a novel view on the pathogenesis of meningeal carcinomatosis and clinical presentation of neurenteric cysts, highlighting the value of meningeal biopsy in chronic meningitis of unknown causes.

A practical overview of CT and MRI features of developmental, inflammatory, and neoplastic lesions of the sphenoid body and clivus

The sphenoid bone is an unpaired bone that contributes to the formation of the skull base. Despite the enormous progress in transnasal endoscopic visualisation, imaging techniques remain the cornerstones to characterise any pathological condition arising in this area. In the present review, we offer a bird's-eye view of the developmental, inflammatory, and neoplastic alterations affecting the sphenoid body and clivus, with the aim to propose a practical diagnostic aid for radiologists based on clinico-epidemiological, computed tomography, and magnetic resonance imaging features.

Neurenteric cyst of the dorsal craniocervical junction in an adult: A case report and operative video

Background:

Neurenteric cysts (NCs) are rarely located in the dorsal craniocervical junction (CCJ).

Case Description:

Here, we present a case and show the surgical video of a 24-year-old man with a history of neck pain, progressive hemiparesis, and difficulty swallowing. Radiological images revealed an intradural extramedullary lesion at the dorsal CCJ. Posterior approach with C1–C2 laminectomy for resection of the lesion was performed with significant improvement in symptoms postoperatively. Histopathological examination confirmed the diagnosis of NC.

Conclusion:

This case demonstrates a rare location of a NC in an adult patient. Complete excision of the cyst wall and its content is the recommended treatment option.

Pineal region neuroenteric cyst in a 13-year-old girl: A rare localization with postoperative recurrence and local dissemination

Background:

Neuroenteric cysts are rare cystic benign neoplasms of the central nervous system most often located in the spinal cord and rarely, intracranially. The nonspecific neuroimaging features make management planning potentially challenging. We present a case of a radiologically misdiagnosed neurenteric cyst with a complicated course.

Case Description:

A 13-year-old girl presented with a 6-month history of headache, tinnitus, and dizziness. Initial magnetic resonance images (MRIs) were indistinguishable from a pineal arachnoid cyst with aqueductal stenosis and hydrocephalus. Cyst fenestration was performed through an infratentorial supracerebellar approach. Histology revealed a neurenteric cyst. On day 10 postoperatively, she deteriorated with acute hydrocephalus and cyst enlargement. An external ventricular drain was inserted. She remained asymptomatic thereafter. At 1-year postoperative, the patient remains asymptomatic despite the MRI showing cyst enlargement and local dissemination in the form of multiple cystic lesions in the cerebellum along the operative corridor. The patient was managed conservatively considering adhesion noted intraoperatively.

Conclusion:

Neuroimaging features of brain cystic lesions may be nonspecific. Special attention should be awarded to posterior fossa and paramedian cystic lesions. Rarer lesions like neurenteric cysts should also be considered. When in doubt, we recommend using the following methods to prevent the free outflow of the cyst contents into the subarachnoid space: lining the cyst and operative corridor with cotton wool and puncture opening and suctioning of fluid. However, the “gold standard” remains surgical treatment with radical excision of the endodermal cyst capsule. It is necessary to preassess the possibility of total or subtotal resection.

Supratentorial Neurenteric Cysts: Systematic Literature Review and Case Report

BACKGROUND

Neurenteric cysts (NC) are uncommon, congenital lesions with histopathologic properties derived from the gastrointestinal or respiratory tract. They are typically located in the intradural extramedullary compartment but rarely seen in the supratentorial region. The occurrence of supratentorial NCs (S-NC) presents an interesting quandary regarding their embryopathogenesis.

METHODS

We present a case report and systematic literature review on S-NCs following PRISMA guidelines.

RESULTS

A 57-year-old woman presented with a seizure and paresthesias of the face, hands, and feet. MRI revealed a right temporo-occipital cystic lesion, which was managed with surgical resection. Histologically the cyst was Type A. The patient is without recurrence at 10 months. Including this case, 88 S-NCs are reported in the literature. Common presenting symptoms are headaches and seizures. They were mostly treated with craniotomy, preferably with gross total resection (GTR), although sub-total resection (STR) may be necessary due to adhesions. Resection usually led to symptom improvement (61%). Malignant transformation was seen in 3%. Recurrence was seen in 17%, with a mean time to recurrence of 4.2 years, and was significantly more common after STR than GTR.

CONCLUSIONS

If surgically resected, the cyst wall specimen should be sent for pathology review, because of the potential risk for malignancy. If conservatively managed, serial imaging is warranted to track for changes that may indicate transformation. The embryopathogenesis of these rare congenital lesions remains incompletely understood, but the most comprehensive theory involves enteric cell migration to the neuroectoderm during embryogenesis.

Neurenteric Cyst of the Posterior Cranial Fossa: A Case Report and Literature Review

Neurenteric cysts (NCs) are rare benign endodermal lesions of the central nervous system (CNS), most commonly found in the spinal cord. Intracranial lesions are rare, among which the posterior fossa appears to be the predominant location.

We present a case of a 60-year-old man who presented with a suddenly decreased level of consciousness. After a series of radiological studies were done, a multilobulated cystic lesion in the right posterior fossa was observed. Surgical resection was performed and based on its histopathological characteristics, NC diagnosis was confirmed.

Because of the wide list of differential diagnoses and low specificity of radiological features, surgical gross total resection remains the most effective treatment, followed by diagnosis confirmation through histopathological techniques.

Supratentorial Intraparenchymal Neurenteric Cyst Treated by Neuroendoscopic Fenestration: A Case Report and Review of Literature

Neurenteric cysts (NCs) are rare benign congenital neoplasms in the central nervous system that originate from endodermal elements. NCs are more commonly located in the spine than in the brain. Although almost all intracranial NCs are found in the posterior fossa, some have reported supratentorial NCs. The complete excision of the cyst wall is suggested as a curative treatment; however, endoscopic treatment is less discussed. We present a supratentorial intraparenchymal NC in the frontal lobe treated by neuroendoscopic fenestration and review the literature regarding supratentorial NCs. A 43-year-old woman presenting with right hemiparesis and gait disturbance who was found to have a huge cystic lesion with calcification in her left frontal lobe underwent endoscopic fenestration to the ipsilateral lateral ventricle and biopsy. The histopathological diagnosis was consistent with NC. Postoperatively, her right hemiparesis and gait disturbance disappeared. Postoperative MRI showed shrinkage of the cyst. She was discharged without neurological deficits and no recurrence was seen 1 year after surgery. To the best of our knowledge, there have been no reports of a supratentorial intraparenchymal NC treated by neuroendoscopic fenestration. Minimally invasive treatments, such as neuroendoscopic cyst fenestration, can be considered depending on the location of the cyst.

Combined endoscopic endonasal transtubercular and transclival approaches for large neurenteric cyst in posterior cranial fossa: A case report and literature review

Background:

Intracranial neurenteric cysts (NCs) are extremely rare tumors that more commonly involve the posterior fossa than any other cranial part. While transcranial skull base surgery has been the mainstay of treatment, the utility of endoscopic transnasal surgery (ETS) remains to be established.

Case Description:

We report a case of a large posterior fossa NC extensively involving the suprasellar region, cerebellopontine angle, and prepontine cistern, which we successfully resected with ETS through a combination of transtubercular and transclival routes. Before surgery, the patient presented with abducens nerve and pseudobulbar palsies, which resolved within 2 weeks postoperatively. The patient remained free from recurrence for 3 years postoperatively.

Conclusion:

Extended ETS may offer a minimally invasive option for the posterior fossa NC, extensively occupying the ventral space of the brainstem.

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.

Intracranial neurenteric cyst with post-operative chemical meningitis and vagal nerve palsy

Intracranial neurenteric cysts are rare congenital lesions that, though benign, are difficult to diagnose radiologically given their similar imaging appearance to other intracranial cystic lesions. We present a case of a 21-year-old female with a pathologically proven, symptomatic neurenteric cyst in the premedullary cistern. Superimposed on this uncommon diagnosis were also rare post-operative complications of chemical meningitis and vagal nerve injury. We review the current literature surrounding intracranial neurenteric cysts, their imaging characteristics, differential diagnosis, therapeutic options, and potential complications related to their resection.

Anterior Craniocervical Junctional Neurenteric Cyst

Intracranial neurenteric cyst at the anterior craniocervical junction is very rare, and its treatment and prognosis have not been established. We report a case of neurenteric cyst at the anterior craniocervical junction and review the relevant literature. A 16-year-old girl presented with a 2-month history of slowly progressive headache. MRI revealed a well-defined intradural extramedullary cyst in the anterior medulla and brain stem with C1 cord compression. We performed gross total resection of the cyst using a far-lateral transcondylar approach. Surgical resection is the treatment of choice for neurenteric cysts at anterior craniocervical junction, the far-lateral transcondylar approach might be the optimal surgical approach.

Fenestration of intracranial neurenteric cyst: A case report

Background:

Neurenteric cysts are rare congenital lesions of endodermal origin which result from the failure of the neurenteric canal to close during embryogenesis. The majority of neurenteric cysts occur in the spinal cord, though in rare instances can occur intracranially, typically in the posterior fossa anterior to the pontomedullary junction (80%) or in the supratentorial region adjacent to the frontal lobes (20%).

Case Description:

We present the case of a 75-year-old woman with an extra-axial cystic lesion centered in the premedullary cistern causing brainstem compression. The lesion was later histopathologically confirmed to be a neurenteric cyst. She presented initially with a 4-month history of worsening headache, dizziness, and unsteady gait. We performed a left retrosigmoid craniotomy for cyst fenestration/biopsy with the aid of operating microscope and stealth neuronavigation. Following the procedure, the patient recovered without complications or residual deficits.

Conclusion:

This case illustrates the successful fenestration of an intracranial neurenteric cyst with good clinical outcome. We present the pre- and post-operative imaging findings, a technical video of the procedure, histopathological confirmation, and a brief review of the relevant clinical literature on the topic.

Intra-axial Neurenteric Cyst of Medulla: Case Report and Literature Review

Neurenteric cysts (NCs) are rare congenital lesions that are thought to result from the persistence of the neurenteric canal connecting primitive gut and neural tube. Despite the congenital nature, NCs can be diagnosed at any age and at a similar frequency in women and men. To our knowledge, 140 intracranial NCs, confirmed by histology, including the patient presented in this review, have been reported since 1952. Parenchymal NCs are extremely rare, and there are no publications describing the intra-axial NCs of the brainstem at the moment.

A 19-year-old female presented to the clinic with the following complaints: moderate dysphagia (two to three times per day) for and liquids and solids, dysphonia, vertigo, spontaneous nystagmus, imbalance, and numbness in the left side of the body, including the face. The magnetic resonance imaging (MRI) of the brain showed a well-defined lesion centered in the medulla. The patient underwent a small right-sided keyhole retro-sigmoid craniotomy. Just under the sulcus, a cyst containing pathological amorphous gray-yellow liquid was evacuated. Accessible parts of the capsule were resected without brain injury. Residual particles of the capsule were coagulated.

Two months after the operation, the patient presented with similar symptoms. We used the previous craniotomy during the second surgery. After the evacuation of the cyst, a silicone stent was set for connecting with the cerebellopontine cistern and preventing new synechiae formation. As surely as after the first surgery, all neurological symptoms gradually regressed. In two months after surgery, deglutition and sensations recovered, and hemiparesis and imbalance decreased. Postoperative MRI examination two months after surgery showed no evidence of cyst recurrence.

Intra-axial NCs are a rare group of congenital pathological lesions with a favorable prognosis. There are no publications of brainstem NCs with intra-axial localization to date. The treatment of choice in this group of patients is complete microsurgical excision followed by long-term observation.

[Nonneoplastic lesions of the spinal canal]

Numerous vascular, inflammatory, degenerative and tumorous lesions of the spinal canal can cause paraplegic symptoms. In addition to the neurological examination and the leading symptoms, the first topographical classification of the (suspected) disease is essential for further diagnostics. Hence, high-resolution magnet resonance imaging (MRI) is the gold standard for the majority of questions. To avoid diagnostic and therapeutic mistakes, differentiation of intraspinal tumors from tumor-like (nonneoplastic) lesions is indispensable, which is often only possible after follow-up imaging or surgical exploration.

Huge Ventral Cervicomedullary Neurenteric Cyst: A Rare Entity with Good Surgical Outcome and Appraisal

Neurenteric cysts are rare congenital lesions of benign nature that can be encountered at any level of the neuraxis, starting from the cranium down to coccyx. Rewarding outcome can be achieved with early diagnosis and complete removal of these benign lesions. Here, we report a case of a huge neurenteric cyst in an 11-year-old boy at the ventral craniocervical junction, a rarely reported entity with literature review. In this article, we focus on the clinical presentation, pathogenesis, radiological findings, surgery, and surgical outcome of this benign lesion, as we succeeded to have gratifying result following surgery in our instance.

Endodermal Cysts of the Central Nervous System: Review of the Literature and a Case Report

Context

Endodermal cysts are rare benign developmental cysts lined by mucin-secreting and/or ciliated, cuboidal, or columnar epithelium of probably endodermal origin.

Aims

Endodermal cysts are rarely intracranial, frequently located in the posterior fossa. Supratentorial location is the most infrequent and only few cases are reported in the literature, included our case.

Settings and Design

The authors report a case of intracranial supratentorial endodermal cyst with a review of the literature.

Subjects and Methods

A 40-year-old woman was admitted to our department because of progressive gait disorder for 3 months due to right brachial and crural motor deficit associated to right crural sensory disorder (tactile hypesthesia) and right Babinski response at neurological examination due to an endodermal cyst located in the left frontoparietal convexity.

Discussion

Total resection of endodermal cysts is recommended, despite their location and adhesion to the surrounding structures, due to its high risk of recurrence. Fenestration of the cystic content into the subarachnoid cistern may cause obstructive hydrocephalus or chemical meningism.

Results

Although rare, surgeons should be aware that these lesions must be differentiated clinically, radiologically, and histologically from other supratentorial cystic lesions.

Intracranial neurenteric cyst: A case report and differential diagnosis of intracranial cystic lesions

Neurenteric cysts are uncommon, benign lesions that are rarely located intracranially. These cysts are likely due to aberrant embryologic development of the notochord. Clinically, neurenteric cysts may present with symptoms of mass effect, or they can be asymptomatic and incidentally discovered. Imaging features of neurenteric cysts have significant overlap with other intracranial cystic lesions, which can make diagnosis difficult. We present a case of a 35-year-old female with a histopathologically confirmed neurenteric cyst in the premedullary and left cerebellomedullary cistern, with associated symptoms of headache, dizziness, tinnitus, and dysphagia. The patient underwent surgical resection, with improvement in symptoms. We present a review of literature, and a discussion of typical features of multiple intracranial cystic lesions. We hope to promote accurate preoperative diagnosis, to allow for appropriate surgical technique to reduce the risk of recurrence.

Upper cervical spinal bronchogenic cyst: A rare lesion at an exceptional location

An intraspinal bronchogenic cyst is a rare but important cause of compressive cord myelopathy, commonly seen in the cervicothoracic spine. We report a case of a 30-year-old female, presented with complaints of neck pain and progressive weakness of the extremities. The magnetic resonance imaging of the cervical spine revealed an intradural extramedullary, well-defined, multiloculated, cystic lesion in the upper cervical canal extending from the C2 to C5 vertebral levels. To our knowledge, only 11 cases of spinal bronchogenic cysts have been reported in the literature so far. We discuss the rare location of this unusual lesion, possible embryological reasons, and the overall surgical outcome.

Endodermal Cyst with a Non-enhancing Nodule in the Quadrigeminal Cistern Developed in an Octogenarian

BACKGROUND

Intracranial endodermal cysts are congenital lesions that generally develop in the cerebellopontine angle and ventral brainstem of the posterior fossa, whereas endodermal cysts in the quadrigeminal cistern are very rare. We report a rare case of an endodermal cyst in the quadrigeminal cistern with a non-enhancing nodule that developed in patient over 80 years of age.

CASE DESCRIPTION

An 85-year-old man presented to our hospital with progressing gait disturbance and urinary incontinence. Preoperative images showed a cystic mass lesion with a nodule in the quadrigeminal cistern and hydrocephalus. There was no enhanced portion in the lesion, and the intensity of the cyst on magnetic resonance imaging revealed a high protein concentration. Subtotal resection was performed due to the adhesion of the cyst to the brainstem. It was diagnosed as an endodermal cyst. The postoperative course was uneventful, and hydrocephalus improved.

CONCLUSIONS

This is a rare case of an intracranial endodermal cyst in terms of location and age of onset compared with previous reports. This case demonstrates that endodermal cysts should be considered as a differential diagnosis for lesions in the quadrigeminal cistern with high protein concentration in the cyst and nodule representing chronic inflammation, regardless of enhancing effects.

Spontaneous, Intrasphenoidal Rupture of Ecchordosis Physaliphora with Pneumocephalus Captured During Serial Imaging and Clinical Follow-Up: Pathoanatomic Features and Management

BACKGROUND

Ecchordosis physaliphora (EP) is a congenital, uniformly asymptomatic, hamartomatous lesion of the primitive notochord. Herein we report, to our knowledge, the first credible case report of unprovoked intrasphenoidal rupture resulting in recurrent pneumocephalus and cerebrospinal fluid leak, definitively captured over serial imaging during clinical and radiologic surveillance.

CASE DESCRIPTION

A 68-year old woman with Marfan syndrome presented to the emergency department with the worst headache of her life. Imaging demonstrated extensive pneumocephalus and revealed a small, dorsal midline clival lesion consistent with EP and a transsphenoidal defect. Remote imaging encounters confirmed typical EP without pneumocephalus or cortical defect, and an uneventful clinical course years preceding presentation. Over the ensuing months during neurosurgical follow-up, the patient reported recurrent headaches, imbalance, and unprovoked clear rhinorrhea. Further imaging demonstrated an apparently enlarging transsphenoidal defect which was managed by endoscopic transnasal resection and nasoseptal flap. Pathologic evaluation confirmed the diagnosis of EP and chronic dural defect.

CONCLUSIONS

This represents, to our knowledge, the first unambiguous example of spontaneous EP rupture and recurrent pneumocephalus captured over serial imaging. The case further underscores rare but potentially significant complications of EP and highlights management options.

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.

Bronchogenic Cyst: Skull Base Lesions with Extracranial Extension

BACKGROUND

Intracranial bronchogenic cysts (BCs) are extremely rare. To our knowledge, this is the first report of a BC in which lesions involve the middle and posterior cranial fossa, as well as the infratemporal fossa.

CASE DESCRIPTION

We present the case of a 38-year-old woman who suffered from a cranial nerve dysfunction for 2 years. Magnetic resonance imaging showed that there were skull base communication lesions across the middle and posterior fossa. The patient was operated on through an infratemporal fossa approach. The final diagnosis was BC after histopathologic examination and immunohistochemical verification. The patient's neurologic dysfunction was partially ameliorated at the half-year follow-up.

CONCLUSIONS

Intracranial BCs are rare. However, they should be considered in the differential diagnosis for cystic lesions with edge enhancement or extracranial extension.

A Dorsally Located Endodermal Cyst in the Foramen Magnum Mimicking an Arachnoid Cyst: A Case Report

INTRODUCTION

Endodermal cysts are congenital benign cystic lesions in the central nervous system and cause various symptoms. Although some have been reported in the posterior fossa, endodermal cysts located dorsal to the brainstem are extremely rare.

CASE PRESENTATION

The case was of a 10-year-old girl who presented with bilateral upper limb weakness and tremor. Magnetic resonance imaging demonstrated a 4.5-cm cystic lesion with T1-weighted hypointense and T2-weighted hyperintense content in the midline of the cisterna magna dorsal to the medulla oblongata. The cyst was cerebrospinal fluid-like, causing us to suspect a symptomatic arachnoid cyst. The lucent cyst wall had no apparent attachment, and complete recovery ensued following total excision of the cyst wall. Pathology confirmed a diagnosis of endodermal cyst.

DISCUSSION/CONCLUSION

Herein, we review the past literature on this rare entity. An endodermal cyst in the cisterna magna tends to be less strongly attached and to show a cerebrospinal fluid-like component on magnetic resonance images that mimics an arachnoid cyst. The characteristics of dorsally located endodermal cysts may differ from those in other locations.

A novel management proposal for intrinsic brainstem neurenteric cysts: case report

Neurenteric cysts (NCs) are rare congenital lesions with epithelial mucin-secreting walls. They can occur anywhere along the neural axis, and an intrinsic midbrain cyst is extraordinary. Surgical management may pose a challenge due to the location of the lesion and adhesion of the cyst wall to the surrounding brainstem. The authors describe the first case of pediatric NC that was treated successfully with intracystic interferon-α (IFN-α).A 16-month-old baby girl presented with a 2-week history of progressive croup, vomiting, and swallowing difficulty. MRI revealed a 1.8-cm cystic intrinsic lesion in the pontomedullary region. She initially underwent posterior fossa craniotomy and drainage of the cyst under intraoperative neurophysiology monitoring. Three weeks following the procedure, her symptoms recurred, and follow-up MRI demonstrated cystic recurrence. She underwent repeat aspiration of the cyst and biopsy of the cyst wall, and INF-α-2b was injected into the cystic cavity. Her symptoms improved and completely resolved after 5 months. A 9-month follow-up brain MRI study showed complete resolution of the NC. Intracystic IFN-α injection after cystic content aspiration may be a safe treatment option for the management of intrinsic brainstem NCs. Long-term clinical and radiological follow-up is recommended.

A rare presentation of a pediatric neurenteric cyst as an intra-axial pontine lesion: A case report with a 5-year follow-up

Background

Intracranial neurenteric cysts are rare, benign, and slow-growing tumors. However, we encountered a pediatric case that the cyst expansion occurred in a short period of time resulting in rapid deterioration of the patient's symptoms.

Case Description

A previously healthy 7-year-old girl had a week history of dysarthric speech and diplopia along with headaches. Her magnetic resonance images (MRI) showed an abnormal cystic mass in her brainstem. Her symptoms were deteriorated for 1 month and her second MRI revealed an enlargement of the cystic lesion. The tumor biopsy and cyst drainage were carried out and histopathological examination of the cyst wall showed columnar epithelium containing ciliated cells. The final diagnosis of her tumor was neurenteric cyst.

Conclusion

We report a pediatric case of a neurenteric cyst in the brainstem, which expanded in a short period, and review this rare entity.

Supratentorial neuroenteric cyst in children: a case report and brief literature review

Neurenteric cysts are rare developmental lesions typically found outside the central nervous system but when they do, we most likely find them in a spinal (cervical or dorsal) intradural extramedular location, often associated with dysraphism. The more unusual intracranial cases have been published because of its rarity, occurring mostly as a posterior fossa extra-axial cyst, in adults. Supratentorial cases are distinctly infrequent, especially in children, resulting in few case reports and even fewer case reviews. We describe a case of a child with a supratentorial neurenteric cyst and present a brief review of the literature about these cysts in children, a noticeable gap in the literature.

CERVICAL NEURENTERIC CYST: A CASE REPORT

ABSTRACT Objective Neurenteric cysts account for 0.7–1.3% of all spinal cord tumors. These rare lesions are composed of heterotopic endodermal tissue. Methods A 26-year-old woman with a 13-month history of severe cervicalgia and brachial paresthesia. Clinically she had mildbilateral brachial paresis (4/5), generalized hyperreflexia and a left Babinski Sign. Past medical history was significant for a cervical fistula closure when she was 1yearold. The superior somatosensory evoked potentials revealed medullary axonal damage with a left predominance. A cervical magnetic resonance imaging of the neck was performed showing a dorsal homogeneous cystic intradural extramedullary lesion with high signal intensity on T2. Computed tomography revealed a Klippel-Feil syndrome. Results A posterior laminectomy and surgical excision were performed without complications. Post-operative follow-up showed a complete recovery of arm strength. The histopathological report confirmed the preoperative diagnosis of neurenteric cyst. Most neurenteric cysts are located in the spine, mainly in a ventral position. A total of 95% of neurenteric cysts are found in the intradural/intramedullary compartment. Symptomatic neurenteric cysts typically appear in the second and third decades of life and are 1.5 to 3 times more common in men. In 50% of the cases, other vertebral malformations have also been reported. In this case, a congenital dorsal enteric cyst and a Klippel-Feil syndrome were observed. Conclusions The intraspinal neurenteric cysts are rare lesions that must be included in the differential diagnosis of a dorsal, intradural cystic structure. The diagnosis may be overlooked, especially in cases of chronic neck pain without neurological deficit. Level of evidence V; Expert Opinion.

[Spinal cysts : Diagnostic workup and therapy]

CLINICAL ISSUE

Spinal cysts can be classified as meningeal, not meningeal, and tumor-associated cysts. Due to the widespread availability of high-resolution computed tomography and magnet resonance imaging, spinal cysts can be detected with high sensitivity these days. Concerning the variety of potential cystic differential diagnoses, a precise classification is difficult and can often only be realized after surgical inspection or histological examination.

PRACTICAL RECOMMENDATIONS

Spinal cysts are generally incidental findings during a routine diagnostic workup and need no further therapy. Surgical treatment can be necessary if the spinal cyst reaches a certain size and causes neurological symptoms due to the compression of the spinal cord or the nerve root.

Supratentorial Neurenteric Cyst: A Rare Differential for a Frontal Cyst

Supratentorial neurenteric cyst is a rare entity. They are usually isointense to slightly hyperintense on T1W images and hyperintense on T2-weighted/fluid attenuated inversion recovery images. There was a diagnostic dilemma in this case due to the cerebrospinal fluid intensity of the cyst on magnetic resonance imaging. Postoperative residual lesion predisposes to hemorrhage and seizures.

A suprasellar colloid cyst over an 11-year follow-up: case report and literature review

BACKGROUND

Colloid cysts (CCs) are rare cystic lesions derived from the endoderm of the central nervous system. Although they appear most commonly in the anterior roof of the third ventricle, there are only a few reports of CCs located in the suprasellar region. Although CCs are considered to be slow-growing benign tumors, their developmental process remains unclear.

CASE DESCRIPTION

A 6-year-old boy was referred to our hospital for a mild head injury. Head computed tomography scan revealed a round, hyperdense suprasellar lesion, while magnetic resonance (MR) imaging depicted the mass as an isointense lesion with multiple highly hypointense spots on T2-weighted imaging. Although this lesion had been managed conservatively with annual MR imaging follow up, its size gradually increased, resulting in an increase in diameter by a factor of 1.5 over an 11-year period. The doubling time of this tumor was estimated to be approximately a 7 years. Despite its asymptomatic nature, the cystic lesion was totally resected when the patient was 17 years of age using an endoscopic endonasal approach to make a definitive histological diagnosis and prevent the occurrence of neurological symptoms. The postoperative course was uneventful, and the histological diagnosis of the surgical specimen was consistent with CC.

CONCLUSIONS

This case suggests that CC may be one of several possible diagnoses in patients who present with suprasellar cystic lesions. Even if CCs in the suprasellar region remain asymptomatic, radiological follow-up is required due to possible progressive enlargement of the cyst.

A midline prepontine cyst: Serial magnetic resonance imaging over 20 years shows very slow growth after its rapid shrinkage

An otherwise healthy 22-month-old boy suffered high fever, irritability, nausea, dysphagia, dysarthria and right hemiparesis. Magnetic resonance imaging showed a cystic mass, 15 mm in diameter, with surrounding oedema in the base of the lower pons. The symptoms subsided in about 10 days after onset, followed by a rapid decrease of the cyst size to 5 mm. Thereafter, the patient's psychomotor growth has been normal. Annual follow-up magnetic resonance imaging scans showed very gradual enlargement of the cyst located on the ventral surface of the pontomedullary junction, reaching 16 mm in diameter in 21 years after onset. It was hyperintense on T1-weighted and isointense on T2-weighted magnetic resonance imaging. No haemosiderin deposition or gadolinium enhancement was seen. This is a rare report of a two decade longitudinal follow-up of a midline prepontine cyst showing asymptomatic and very slow growth. The possible nature of the cyst includes neurenteric, dermoid and epidermoid cyst.

[Intracranial neurenteric cysts: experience of the Burdenko Neurosurgical Institute in the XXIth century]

We present a series of cases of a rare pathology, intracranial neuroenteric cysts, a review of the international literature, and the experience in treating this pathology.

MATERIAL AND METHODS

Seven patients with intracranial neuroenteric cysts underwent surgery at the Neurosurgical Institute in the period between 2000 and 2015.

CONCLUSION

The main and only technique for treatment of intracranial neurenteric cysts is their resection.

An intradural extramedullary bronchogenic cyst in the thoracolumbar spine: A case report

RATIONALE

We report the symptoms beginning with weakness and the clinical courses of a patient who was diagnosed with an intradural extramedullary bronchogenic cyst.

PATIENT CONCERNS

The patient was a 44-year-old man visited the Department of Physical Medicine and Rehabilitation for walking difficulties characterized by limping due to muscle weakness of left lower extremity for 5 months and atrophy in left calf muscle.

DIAGNOSES

Lumbar spine MRI was repeated, since radiating pain in the left hip and posterior thigh with low back pain developed 16 months later. Intraspinal mass of T12 and L1 levels that was not found in the first MRI was newly found in the follow-up MRI.

INTERVENTIONS

Total tumor removal was conducted with laminectomy. It was finally diagnosed as an intradural extramedullary bronchogenic cyst on the basis of the pathological analysis results.

OUTCOMES

His left calf circumference was increased compared to before surgery the radiating pain also disappeared.

LESSONS

If the patient's MRI findings are not correlated with the electrophysiologic and physical examination findings, additional MRI should be accompanied with other tests for an early detection.

Intracranial Enterogenous Cysts Close to the Brainstem Treated Through the Nerve Endoscope

Enterogenous cysts (ECs) are rare, inborn lesions of central nervous system, which mostly occurred in the ventral side of the spinal cord as well as common in children; adult intracranial cysts are rare. Although the morbidity of intracranial ECs is quite low, we also can make a preliminary diagnosis of those patients with the help of imaging examination. In this article, we introduced 1 case of ECs ventral to the brainstem, which present images on magnetic resonance imaging as hypointense lesions on T1-weighted and high-intensity mass on T2-weighted image. In consideration of the difficulty of the surgical approach and the surgical visual field exposure, we use microscope and nerve endoscope to design personalized surgical approach to minimize the surgical injury. Pathologic examination showed that it was typical EC. Not only is the location extremely rare, but also the surgical method is uncommon in this disease. We not only study the intracranial ECs' manifestations, but also discuss the surgical approach and the application of nerve endoscope of our choice,which aims to provides a new surgical therapeutic approach for these lesions.

Fourth Ventricle Neurenteric Cyst Mimicking Hemangioblastoma

This report presents a case of fourth ventricle neurenteric cyst (NE cyst) mimicking hemangioblastoma, which developed in a 50-year-old woman. A tiny enhancing mural portion of the fourth ventricle in MRI suggested that the cyst was hemangioblastoma, but pathological evidence showed that the cyst was in fact NE cyst in the fourth ventricle. In order to make proper decision on to what extent of surgical resection should be done, considering every possibility in differential diagnosis might be helpful. This case reports an unusual pathology in 4th ventricle, considering the patient's age, and demonstrates that a rarer disease may share radiological features of a common disease.

Intracranial neurenteric cyst mimicking an ependymoma: imaging features, pathologic correlation and review of literature

We present a case of a 57-year-old female with four-months of diplopia and vertigo. MRI revealed a mixed cystic and solid partially enhancing lesion of the 4th ventricle, foramen of Luschka and cerebellopontine angle. Preoperative differential diagnosis favored ependymoma. Biopsy revealed a neurenteric cyst, a benign developmental lesion that rarely occurs intracranially. This case highlights several atypical manifestations of intracranial neurenteric cyst, with regions of histologically benign solid enhancement, multicompartmental extra-axial location mimicking an ependymoma, and rapid recurrence without evidence of underlying malignancy.

Spinal neurenteric cyst in a dog

CASE DESCRIPTION An 11-year-old English Cocker Spaniel was evaluated because of chronic progressive ataxia of the hind limbs. CLINICAL FINDINGS The dog had no history of previous illness, and findings of physical examination and laboratory tests were unremarkable. Neurologic examination revealed that the dog was ambulatory with severe ataxia of the hind limbs. Proprioception was decreased in the right and left hind limbs (right affected more than left), and spinal reflexes were bilaterally unremarkable. Moderate signs of pain were detected during palpation of the lumbar portion of the vertebral column. Findings suggested a lesion within the thoracolumbar or lumbar segments of the spinal cord. Magnetic resonance imaging revealed extradural spinal cord compression attributable to an extradural space-occupying lesion originating from or infiltrating the L4 lamina on the right side. TREATMENT AND OUTCOME Hemilaminectomy was performed to remove the extradural lesion. Histologic findings for tissue samples collected during the procedure were consistent with a neurenteric cyst. The late onset and progression of clinical signs of this rare congenital malformation were suspected to have been the result of enlargement of the neurenteric cyst through continuous production of mucus by goblet cells. The dog responded favorably to surgical decompression and was clinically normal 1 year after surgery. It was euthanized 2 years after surgery for an unrelated reason (end-stage heart disease), and no neurologic deficits were evident before that point. CLINICAL RELEVANCE Congenital neurenteric cysts should be considered as a differential diagnosis for neoplastic disease in dogs in which results of diagnostic imaging indicate the presence of an extradural mass affecting vertebral structures.