Recurrence of a neurenteric cyst with malignant transformation in the foramen magnum after total resection. Case report

Tumor-Like Lesions in the Craniovertebral Junction: A Case Series, Systematic Review, and Meta-Analysis

Background: Tumor-like lesions at the craniovertebral junction mimic tumors in clinical presentation and imaging. Our study focuses on three common developmental pathologies-epidermoids, dermoids and neurenteric cysts. Methods: We conducted a retrospective analysis of a case series and a meta-analysis of 170 patients from 119 reports. Results: Neurenteric cysts predominated (81.2%). Anterior cysts were linked to neurenteric cysts, while posterior ones correlated with dermoid/epidermoid cysts (p < 0.001). Complications occurred in 27.2% of cases, with cranial nerve paresis being the most common. Most patients had excellent outcomes (75.2%) with low recurrence rates (12%). Dermoid cysts were more associated with anomalies (p < 0.001). Among 138 neurenteric cyst cases, 15 experienced recurrence, with predictors including ages 51-60 and over 70, subtotal resection, complications, and poor outcomes (p < 0.001). Cysts with total resection were significantly less likely to adhere to surrounding brain tissue (p < 0.001). CSF diversion was correlated with older age (p = 0.010) and various complications (p < 0.001). Age affected outcomes, and the hydrocephalus was linked to poor outcomes (p = 0.002). Conclusions: This meta-analysis underscores the importance of total resection in minimizing recurrence rates and emphasizes meticulous preoperative planning and imaging. Our results indicate that rim enhancement (p = 0.047) and poor outcome (p = 0.007) are significant factors associated with recurrence. Additionally, associated anomalies, as well as the patient's age and overall health, significantly influence the surgical outcomes and the likelihood of recurrence.

A Neuroenteric Cyst of the Cavernous Sinus: A Case Report

Background  Neuroenteric cysts (NECs) are benign lesions mostly found as intradural extramedullary lesions in the cervicothoracic spinal cord. NECs in the cavernous sinus are very rare. To the best of our knowledge, this is only the second reported case and the first in an adult. Presentation  We present a left cavernous sinus NEC in a 75-year-old female with gradually worsening headache and facial pain unresponsive to medical treatment. Imaging revealed a cystic mass lesion in the left cavernous sinus encasing the distal petrosal and cavernous segment of the internal carotid artery. Initial differential diagnoses included more common pathologies located near the cavernous sinus, including cystic schwannoma, craniopharyngioma, and dermoid and epidermoid tumors. The patient underwent a left pterional craniotomy with an extradural transcavernous approach for surgical exploration and possible resection of this mass lesion. Histopathology revealed an NEC lined with benign respiratory-type epithelium. Postoperative imaging revealed gross total tumor resection. The patient remained neurologically intact with complete resolution of facial pain. Conclusion  We present a rare pathology that can easily be misinterpreted as other types of lesions. NECs should be kept in mind for differential diagnosis of cavernous sinus cystic lesions. The surgical aim should be maximal safe excision.

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

Introduction  Neurenteric cysts (NECs) are rare, congenital lesions lined by endodermal cell-derived columnar or cuboidal epithelium. Based on 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 the extent of capsule resection. Methods  Records were retrospectively reviewed for all patients with radiographic or pathological evidence of intracranial NEC from 1996 to 2021. Results  A total of eight patients were identified; four of eight (50%) presented with headache, and four had signs of one or more cranial nerve syndromes. One patient (13%) presented with third nerve palsy, one (13%) had sixth nerve palsy, and two (25%) with hemifacial spasm. One patient (13%) presented with signs of obstructive hydrocephalus. Magnetic resonance imaging demonstrated T2 hyper- or isointense lesions. Diffusion-weighted imaging was negative in all patients (100%) and T1 contrast-enhanced imaging demonstrated minimal rim enhancement in two patients (25%). In three of eight (38%), a gross total resection (GTR) was achieved, while in four (50%), a near-total resection, and in one (13%), a decompression was performed. Recurrences occurred in two (25%) patients, one with decompression and another with near-total resection, among these 1/2 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 less than GTR recurred, underpinning the importance of maximally safe resection in these patients. Overall patients did well without major morbidity from surgery.

Adenocarcinoma arising in an ectopic enterogenous cyst: A rare case report and review of literature

Enterogenous cyst (EC) is a rare congenital lesion generally located in the central nervous system, such as in the cerebral hemispheres, posterior fossa, or spinal canal. They are usually benign lesions, and malignant transformation is rare. A 42-year-old woman felt an obvious pain in the lump and went to a local hospital for local lumpectomy. After 7 months, she again felt pain in the buttocks and difficulty in urinating and defecation. The computed tomography (CT) scan showed a mass in the pelvis. Sacrococcygeal cyst excision was performed 10 days later, and postoperative pathology showed epidermoid cyst. Shortly after, the patient recovered and was discharged from the hospital; the pain in the buttocks continued to recur. Puncture and drainage were performed five times. Later, the patient went to our hospital for treatment, and pelvic MRI showed multiple abnormal signal shadows in the presacral and sacrococcygeal regions, some of which were considered abscesses, and some were cystic lesions. She underwent tumor resection and was diagnosed with EC with locally moderately differentiated adenocarcinoma. Four months later, the patient's symptoms of swelling and pain recurred. MRI examination showed multiple high-signal T2 shadows in the anterior sacral and subcutaneous tissues of the buttocks, and enhanced scan showed partial marginal enhancement. After assessment, the patient was given a radiation dose of 60 Gy/25F. ECs in the anterior sacral and soft tissue of the buttocks are very rare, and the case of carcinomatous transformation has never been reported. Therefore, we discussed the clinicopathological features of ectopic ECs and reviewed the literature.

Elucidating the multiple genetic alterations involved in the malignant transformation of a KRAS mutant neurenteric cyst. A case report

Neurenteric cyst (NC) shows benign histopathology and rarely demonstrate malignant transformation. We herein describe a case of NC that exhibited malignant transformation. A 65-year-old female presented with gait disturbance due to compression by a cystic mass on the dorsal surface of the medulla oblongata. Partial resection was performed twice, leading to improvement of her symptoms. Two years after the second surgery, gadolinium-perfused T1-weighted magnetic resonance imaging revealed an invasive lesion with contrast enhancement at the trigone of the left lateral ventricle for which partial resection followed by radiotherapy was performed. However, mass regrowth was observed, with the patient eventually succumbing to her disease 11 months after her third surgery. Histopathological analyses of the first and second surgical specimens identified pseudostratified cuboidal epithelial cells, with no nuclear or cellular atypia resembling gastrointestinal mucosa, lining the inner surface of the cystic wall. Based on these findings the lesion was diagnosed as NC. The third surgical specimen exhibited apparent malignant features of the epithelial cells with elongated and hyperchromatic nuclei, several mitotic figures, small necrotic foci, and a patternless or sheet-like arrangement. Based on these findings, the lesion was diagnosed as NC with malignant transformation. Next-generation sequencing revealed KRAS p.G12D mutation in all specimens. Additionally, the third surgical specimen harbored the following 12 de novo gene alterations: ARID1A loss, BAP1 p.F170L, CDKN1B loss, CDKN2A loss, CDKN2B loss, FLCN loss, PTCH1 loss, PTEN loss, PTPRD loss, SUFU loss, TP53 loss, and TSC1 loss. The aforementioned results suggest that KRAS mutation is associated with the development of the NC, and that the additional gene alterations contribute to malignant transformation of the NC.

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.

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.

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.

Predictors for complete surgical resection of posterior fossa neurenteric cysts: A case report and meta-analysis

Background

Incomplete resection of neurenteric cysts (NCs) has been associated with increased recurrence rates in patients compared to complete resection (CR) and information on intracranial NCs appearance on diagnostic imaging is scarce. We sought to identify factors associated with CR and provide the largest up-to-date review of NCs appearances on various diagnostic images.

Methods

Data from Medline, EMBASE, and Web of Science were extracted. Univariate and multivariate logistic regression models were used to analyze factors associated with CR.

Results

A total of 120 publications reporting 162 original cases on posterior fossa NCs met the inclusion criteria for analysis. Eighty-nine (55.6%) of the patients were female, the mean (SD) age of the patients' during operation was 34.3 (16.9) years, and CR was achieved in 98 (60%) of patients. Univariate analysis identified male sex as a statistically significant predictor for complete reaction (OR 2.13, 95% Cl 1.10-4.11, P = 0.02). The retrosigmoid approach (OR 1.89, 95% Cl 0.98-3.63, P = 0.06), far lateral approach (OR 0.46, 95% Cl 0.21-1.02, P = 0.06), and pediatric patient (OR 2.45, 95% Cl 0.94-6.56, P = 0.07) may be possible predictors for CR, however, they were not statistically significant. NCs are mainly hypodense on CT (32 [61.5%]), varied greatly in intensity on T1WI, hyperintense on T2WI magnetic resonance imaging (98 [67.1%]), and hyperintense on fluid-attenuated inversion recovery (17 [63.0%]).

Conclusion

We recommend utilizing various diagnostic imaging tests to help reduce misdiagnoses when identifying intracranial NCs. For patient safety, CR should be achieved when possible, to reduce risk of additional operations due to recurrence.

Early Recurrence of an Infantile Endodermal Oculomotor Nerve Cyst following Surgical Fenestration: A Case Report

INTRODUCTION

Infantile endodermal oculomotor nerve cyst (EONC) is an extremely rare entity. There are very few pediatric cases reported in the literature, and as expected, oculomotor palsy is the most common presenting symptom. To date however, the risk of recurrence of these lesions following surgical intervention is unclear due to a lack of long-term radiological follow-up.

CASE PRESENTATION

We present a case of a 13-month-old male patient with an EONC and detail his surgical fenestration and postoperative course. Somewhat surprisingly, re-expansion occurred within 6 months and remained stable 2 years later.

DISCUSSION

A surgical approach to fenestration of an EONC in an infant is possible and should be performed by an expert neurosurgeon. Early recurrence is underreported in the current literature, and we encourage longer term radiological surveillance of these lesions after surgery to optimize primary and recurrent management in the future.

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.

Spinal endodermal cyst undergoing malignant transformation and marked elevation of serum carbohydrate 19-9 level

Endodermal cyst (EC) is a benign tumor that can arise along the craniospinal axis. Infrequently, ECs undergo malignant transformation. A 43-year-old man presented with numbness in the right arm, leg and occipitalgia. MRI revealed a multicystic, intradural extramedullary tumor at C2 with enhancement along the ventral surface of the spinal cord. Blood test showed an abnormal increase in serum carbohydrate antigen 19-9 (CA 19-9) level. Systemic positron emission tomography-computed tomography was normal. He underwent total tumor resection and was diagnosed with EC. He developed double vision, hearing loss, and swallowing difficulty on postoperative day 70. Cerebral MRI revealed marked extensions of leptomeningeal dissemination. The serum CA 19-9 level increased continuously and finally reached 1515.0 U/ml. He died of respiratory failure on day 108. An autopsy did not reveal abnormalities in the abdominal and chest organs. On microscopic examination, the post-mortem specimen revealed adenocarcinoma. Immunohistochemically, both the surgical and autopsy specimens were positive for CA 19-9. Spinal ECs may lead to malignant transformation with leptomeningeal dissemination that causes abnormal elevation of serum CA 19-9 levels.

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.

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.

Mucinous adenocarcinoma arising from a residual supratentorial neurenteric cyst and expressing mutated KRAS: a case report

Malignant transformation of intracranial neurenteric cysts (NCs) has been reported in only 7 cases, but the molecular characteristics leading to malignant transformation remain unclear. A 61-year-old woman presented with headache and dizziness. Imaging revealed a 10-cm, extra-axial cystic mass in both middle fossae. A partial resection was performed, and the residual mass size gradually decreased. She had repeated ventriculoperitoneal shunts to relieve symptoms of hydrocephalus. Eight years later, follow-up images revealed marked enlargement of the mass and a newly developed lesion. After a second partial resection, a mucinous adenocarcinoma infiltrating the brain was identified. Transitions from benign-looking cuboidal cells to dysplastic cells were observed. A KRAS mutation, which might be associated with malignant NC transformation and was not present in the initial specimen, was identified in the adenocarcinoma. In conclusion, KRAS-mutant mucinous adenocarcinoma may arise in a longstanding residual NC after partial resection.

Recurrent intracranial neurenteric cyst with malignant transformation: A case report and literature review

Neurenteric cysts (NCs) are uncommon congenital cystic lesions. Malignantly transformed NCs are extremely rare. The present study reports the case of a recurrent foramen magnum NC with a malignant transformation and reviews 8 previously reported cases. A 58-year-old woman with a 5-month history of occasional headaches, dizziness and vomiting presented to the Beijing Tiantan Hospital (Beijing, China) with palsy of the left cranial IX and X nerves, decreased sensation in the limbs on the right side and an ataxic gait. Magnetic resonance imaging (MRI) scans revealed a cystic mass in the left side of the foramen magnum, positioned anteriolaterally to the medulla oblongata. Surgery using a left suboccipital retrosigmoid approach was performed. The lesion was partially resected and was histopathologically diagnosed as an NC with focal hyperplasia of the epithelial cells. Additional MRI scans that were performed 25 months later revealed a solid lesion posterior to the medullar oblongata. Therefore, surgery using a suboccipital midline approach was performed. The solid lesion was sub-totally removed and was histopathologically diagnosed as a well-differentiated papillary adenocarcinoma. At 1 month post-surgery, the patient's condition worsened, eventually resulting in mortality due to respiratory failure. Based on the findings of the present case and previous literature, strict criteria for malignant-transformed NCs were created. The location distribution of malignant-transformed NCs does not coincide with the location distribution of all NCs, and malignantly transformed NCs usually occur in adult patients and present as atypical radiological features. Surgery is the optimal treatment for malignantly transformed NCs, and the effectiveness of adjuvant therapy requires additional studies.

Non-metastatic squamous cell carcinoma within a Rathke's cleft cyst

INTRODUCTION

Primary intracranial and sellar squamous cell carcinoma is an extremely rare entity, usually caused by malignant transformation of epidermoid cysts, or very rarely other non-malignant epithelial cysts. Malignant transformation of a Rathke's cleft cyst has never been described.

CASE DESCRIPTION

We present a 49-year-old male patient who presented with a 3-month history of progressive frontotemporal headaches. Imaging revealed a 1.2 cm cystic pituitary mass consistent with a hemorrhagic Rathke's cleft cyst. The patient underwent trans-sphenoidal resection of the pituitary cyst, and pathologic analysis revealed a squamous cell carcinoma lining a Rathke's cleft cyst. Extensive imaging and otorhinolaryngologic evaluation revealed no primary source for metastasis.

CONCLUSIONS

We feel this represents the first case of a patient with a pituitary lesion in which presentation and MRI imaging were consistent with Rathke's cleft cyst, yet histology revealed squamous cell carcinoma in situ.

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.

Malignant Transformation of a Neurenteric Cyst in the Posterior Fossa Presenting with Intracranial Metastasis: A Case Report and Literature Review

Intracranial neurenteric cysts are relatively rare and almost exclusively benign. Here we present a case of an intracranial neurenteric cyst that was histologically benign in the first surgery and later demonstrated significant growth and intracranial metastasis with malignant transformation. A 47-year-old woman presented with a headache, which had gradually worsened over 1 year. Initial magnetic resonance (MR) images revealed a solitary cystic lesion in the left cerebellopontine angle with significant mass effect. Subtotal resection leaving a small mass strongly adhered to the brainstem was achieved. Histopathological diagnosis was neurenteric cyst with no malignant features. This lesion recurred 4 years after the first surgery in the form of a cystic mass adjacent to the brainstem. In addition, histopathological examination of a specimen from the second surgery revealed malignant transformation. The patient declined to undergo radiation therapy and was conservatively managed. Three years after the second surgery, MR imaging showed recurrence of the solid mass. Although the patient had been treated with subtotal resection and radiation therapy, she died with metastatic masses in the right frontal lobe and cervical cord. A specimen from the third surgery revealed diffuse malignant features similar to mucinous adenocarcinoma. Our case and literature review indicate that, although rare, malignant transformation can occur particularly among intracranial neurentreric cysts. This finding suggests the importance of long-term follow-up for subtotally or partially resected intracranial neurenteric cysts.

Impact of DTI tractography on surgical planning for resection of a pediatric pre-pontine neurenteric cyst: a case discussion and literature review

We report a case of a four-year-old male who presented with symptoms of brainstem compression and lower cranial nerve neuropathies. MRI revealed a large, pre-pontine mass causing brainstem compression with an uncertain intra-axial component. Using diffusion tensor imaging (DTI) tractography and other imaging modalities, we were able to confirm that the lesion was extra-axial and did not involve the corticospinal tracts. In addition, DTI tractography illustrated that corticospinal tracts were displaced to the right obligating a left-sided approach. Upon resection, the mass was identified as a pre-pontine, extra-axial neurenteric cyst (NEC), which represents a rare finding in the pediatric population. The patient ultimately did well following the drainage and resection of the cyst wall and had excellent recovery. In this paper, we discuss the pathophysiology of and treatment options for NECs and explain how DTI tractography in our case assisted in planning the surgical approach.

Two-stage approach in the management of thoracic neuroenteric cyst with spinal extension: thoracoscopic excision following dorsal laminectomy

BACKGROUND

Neuroenteric cysts (NC) are rare pathologies and localized generally in posterior mediastinum or abdomen where they may extend to spinal canal through a vertebral defect. Isolated spinal lesions require dorsal/ventral laminectomy and thoracic ones thoracotomy or thoracoscopy. Posterolateral approach via thoracotomy is generally performed for lesions with both thoracic and spinal components. Minimal invasive excision of a thoracic NC with spinal extension in an infant is presented herein.

CASE REPORT

A term female newborn with an antenatal (26th week) diagnosis of congenital diaphragmatic hernia (CDH) was admitted. On physical examination, she was normal except mild dyspnea and CDH were excluded on radiogram. Left parenchymal opacity necessitated thorax tomography that revealed lobulated cystic lesion (6 × 3.5 × 4.5 cm) in posterior mediastinum. MRI showed intraspinal extension of the lesion through a hemivertebrae (6th). Two-stage procedure was planned for suspected neuroenteric cyst. First, intraspinal component was excised with dorsal laminectomy and the connection was closed. Then, the thoracic component was excised thoracoscopically. Histopathological evaluation confirmed the diagnosis. Total parenteral nutrition and high dose somatostatin analog was needed due to transient left chylothorax on postoperative course. She was well and symptom-free in postoperative period.

CONCLUSION

Neuroenteric cysts may lead to misdiagnoses in antenatal period. MRI is critical to show spinal and vertebral pathologies in suspected cases. Thoracoscopy may safely be performed for thoracic lesions with spinal extension in two-stage approach following closure of the connection and excision of the spinal component.

[Orbital neurenteric cyst. A case report and review of the literature]

INTRODUCTION

Neurenteric cysts defined as a cyst lined by endodermal-type epithelium are extremely rare. We report a rare case of an orbital neurenteric cyst.

CASE REPORT

A 19-year-old female presented with an orbital cyst tumor that had cosmetic consequences. The signal of the cyst was not enhanced after administration of gadolinium on MRI examination. The patient underwent surgery due to the increase in size of the tumor. A complete cyst removal including the cyst wall through the inferior palpebral fold was performed. The histological examination confirmed the diagnostic of neurenteric cyst. The patient was discharged home in excellent condition.

CONCLUSION

This report discusses the clinical presentation, neuroradiological aspect, pathological findings and therapeutic consideration of the neurenteric cyst. We described a rare case of orbital neurenteric cyst. Due to the local recurrence rate observed after partial resection, the goal of the surgery should be a total resection of the cyst with the cyst wall.

Mucinous adenocarcinoma arising from supratentorial intramedullary neuroenteric cyst with broncho-pulmonary differentiation

Neuroenteric cysts are benign intradural endoderm cysts lined by gastrointestinal (GI) or tracheobronchial epithelial cells. Their malignant transformation is extremely rare and only six cases have been reported. In these cases, tissue lineage of the cystic endoderm cells giving rise to carcinoma was not clearly identified either as respiratory or as GI type. Herein, we report a case of mucinous adenocarcinoma arising from the neuroenteric cyst with broncho-pulmonary differentiation in the right cerebral hemisphere of a Japanese woman in her late 50s. The cyst wall was entirely lined by the following respiratory epithelial components: stratified bronchial ciliated columnar epithelium with basal cells positive for CK5 and p63, terminal bronchiolar Clara cells positive for thyroid transcription factor (TTF)-1, surfactant B and negative for surfactant C, type I pneumocytes positive for TTF-1, negative for surfactant B and C, and type II pneumocytes positive for TTF-1 and surfactant B and C. In addition, nests of hyperplastic single layered mucinous epithelial cells with bronchial goblet cell phenotype were also demonstrated, and histologic features were almost the same as the pulmonary type I congenital adenomatoid malformation (CCAM) with mucinous epithelial proliferation. The mucinous epithelial nests of type I CCAM are liable to develop mucinous adenocarcinoma and frequently accompany K-ras mutation and expression of p16. However, K-ras mutation and p-16 expression were not detected in this case.

Neurenteric cyst at the craniovertebral junction: A report of two cases

Neurenteric cysts at the craniovertebral junction are extremely rare, in that most are located ventrally in the midline. We report two patients with neurenteric cysts in an unusual location – the lateral craniovertebral junction. The embryological basis, clinical features, imaging characteristics, and management options in these patients have been discussed.

Neurosurgical management of neurenteric cysts in children

OBJECT

Neurenteric cysts (NCs) are endothelium-lined structures of presumed endodermal origin. There have been few pediatric series of intracranial NCs reported previously. The authors present their experience in the management of these lesions.

METHODS

A retrospective chart review of all cases of NCs identified between 1977 and 2007 was carried out. Demographics, details of clinical presentation, surgical therapy, and outcome data were extracted.

RESULTS

Eleven cases were identified, involving 6 girls and 5 boys. The patients' average age was 4.6 years (range 1 day-14 years). Limb weakness was the most common presenting symptom. The location of the cysts was cervical in 2 cases, cervicothoracic in 4 cases, and thoracic in 3 cases. One cyst was anterior to the pons with extension to the left cerebellopontine angle and 1 cyst was at the craniocervical junction. Five patients had an apparently complete initial excision, with 1 recurrence. Four patients were initially treated with incomplete excision and/or cyst drainage, usually into an Ommaya reservoir. A neonate with a large cervicothoracic cyst died of multiple congenital anomalies without any intervention. All other patients were alive at last follow-up. One patient with a radiologically identified presumed cyst, which remained stable, was simply followed up. Several patients required multiple procedures and 1 patient developed hydrocephalus after aseptic meningitis and was treated with CSF shunting.

CONCLUSIONS

Neurenteric cysts are rare in the pediatric population. Total resection, if possible, provides the best long-term outcome. Incomplete excision may lead to multiple procedures, including cyst drainage, but can lead to long-term stability.

Supratentorial neurenteric cyst associated with a intraparenchymal subependymoma

Neurenteric cyst is a rare developmental lesion that very infrequently is localised supratentorially. Intraparenchymal subependymoma is an even more rare benign tumour. The authors report the case of a 45-year-old gentleman with a background of drug resistant epilepsy. An MRI was performed which showed a left frontal cystic lesion with a solid component. Histopathology confirmed a type C neurenteric cyst associated with an intraparenchymal subependymoma. Following enlargement of the lesion and worsening of symptoms he was referred to our institution for further management. A frontotemporal craniotomy was performed for excision of the lesion but recurrence occurred within 1 year. The lesion was further excised and 19 months post re-excision the patient is seizure free with no evidence of recurrence on MRI.

Microsurgical excision of the craniocervical neurenteric cysts by the far-lateral transcondylar approach: case report and review of the literature

Neurenteric cysts in the anterior craniocervical junction (CCJ) region can be found in extremely rare cases. We report one case with craniocervical neurenteric cyst that was excised by the far-lateral transcondylar (FLT) approach. A 43-year-old man presented with a history of recurrent episodes of mild neck pain and dysesthesia in his bilateral hands of 2 years' duration with rapid deterioration 3 weeks prior to admission. Magnetic resonance imaging (MRI) of the CCJ region revealed a well-defined intradural cystic lesion located ventral from the pontomedullary junction to C1 vertebra with medulla and C1 cord compression. This patient underwent total excision of the lesion via the FLT approach without any postoperative neurological deficits, and the histopathologic diagnosis was neurenteric cyst. Follow-up MRI has revealed no evidence of recurrence. The clinical features, imaging studies, and surgical approach options involved in resecting craniocervical neurenteric cysts are discussed, along with a review of the literature.

Neurenteric cyst: an unusual cause of third nerve palsy

INTRODUCTION

Neurenteric cysts are a rare cause of central nervous system compression. Pediatric intracranial cysts are even less common.

CASE STUDY

We describe the presentation, imaging features, surgical management, and postoperative course of a 5-year-old female with congenital third nerve paresis, worsening headaches, and a cyst of the third nerve. We performed an eyebrow incision and keyhole supraorbital craniotomy for exploration and subsequent resection of a neurenteric cyst that was densely involved with the third nerve at its exit from the midbrain. Postoperatively, she had chemical meningitis and complete third nerve palsy. This entity is extremely rare in this location but should be included in the differential. We summarize the current literature on these lesions and recommend biopsy and fenestration as surgical treatment.

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.

The transclival endoscopic endonasal approach (EEA) for prepontine neuroenteric cysts: report of two cases

INTRODUCTION

The transclival endoscopic endonasal approach was used to completely remove a prepontine neuroenteric cyst in two different patients.

CASE REPORTS

Full clinical improvement without postoperative complication was achieved in both cases. The postoperative hospital stay was limited to 2 and 3 days.

DISCUSSION

In comparison to posterolateral skull base approaches, the transclival endoscopic endonasal approach allows direct access to the prepontine cistern without unnecessary manipulation of neurovascular structures at the cerebellopontine angle. In contrast to transoral surgery, patients may have decreased risk of infection and can be fed orally immediately without the risks of palatal and oropharyngeal dehiscence.

CONCLUSION

Neuronavigation technology, strict adherence to microsurgical principles, and significant endoneurosurgical experience are strongly recommended when approaching these challenging lesions.

Neurenteric cyst of the lower clivus

OBJECTIVE

Neurenteric cysts (NCs) typically arise as benign ventral intradural extramedullary developmental malformations of the spine which contain heterotopic epithelium resembling the intestinal or respiratory tracts. Intracerebral NCs are extremely rare, though the frequency of symptomatic reports and incidental findings is increasing, perhaps because of advances in neuroimaging. Recognition of the unique radiographic and histopathologic features of this entity is of growing importance in the treatment of cysts of the neural axis. We present an unusual case of an NC arising at the lower clivus.

CLINICAL PRESENTATION

A 58-year-old man presented with occipitalgia, diplopia, a bilateral hearing deficit, and mild dysphagia. Computed tomography and magnetic resonance imaging demonstrated a 5 x 2 x 3-cm extra-axial cystic midline mass anterior to the brainstem at the lower clivus with posterior cyst wall enhancement.

INTERVENTION

The patient underwent a left lateral suboccipital total macroscopic resection of the lesion. Microscopic examination and histopathologic findings were consistent with a diagnosis of NC.

CONCLUSION

We describe the clinical presentation, imaging, and histopathologic characteristics, and discuss the diagnosis and surgical treatment of this rare lesion and related pathologic entities. Because of the remote possibility of delayed recurrence, even in cases of apparent total cyst wall removal, long-term serial imaging and a consideration of reoperation for recurrences is advisable.

Disseminated neurenteric cyst

This case report presents the unusual holospinal dissemination of a neurenteric cyst, which was successfully treated by fenestration and placement of a subarachnoid-peritoneal (SP) shunt. The patient was a 46-year-old Japanese woman with a history of fourth ventricle neurenteric cysts, which were managed with cyst fenestration in 1996 and 2005. She had been doing well until January 2006, when she developed dizziness and an unsteady gait. A neurological examination revealed a disturbance in the deep sensation of the feet. A neuroimaging evaluation demonstrated multiple cystic lesions in the whole spinal canal, which significantly distorted the spinal cord. Because the spinal cord distortion was the most severe in the lower cervical to upper thoracic areas, a unilateral osteoplastic laminotomy with an endoscopic cyst fenestration was performed in these areas, followed by placement of an SP shunt. The pathological diagnosis was a disseminated neurenteric cyst. There was no malignancy, and the patient has been well, with an improved gait and no signs of peritoneal dissemination, for > 1 year. The present case showed a unique extent of dissemination, which was most likely a secondary characteristic. Neurenteric cysts are well known for their tendency to recur, and total removal is usually difficult because of adhesion of the cyst membrane to important structures. The lesion also compromises cerebrospinal fluid circulation. Cyst fenestration combined with SP shunt placement might be a treatment option in such a case.

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.

Intracranial neurenteric cyst with recurrence and extensive craniospinal dissemination

Neurenteric cyst represents a rare cystic lesion of the central nervous system, and is generally thought to result from failure of separation of neuro-ectodermal and endodermal elements during week 3 of embryogenesis. Although recurrences have been reported, only one case of craniospinal dissemination has previously been reported. We describe a unique intracranial neurenteric cyst with recurrence and dissemination to the spinal cord.

Malignant transformation of intra-cranial epithelial cysts: systematic article review

INTRODUCTION

Epidermoid and dermoid cysts are among the most benign intra cranial tumors. Their malignant transformation into squamous cell carcinoma is rare. The authors reviewed the literature.

MATERIALS AND METHODS

MEDLINE and SCIENCE DIRECT searches, and examination of the references in the selected articles yielded 74 patients, 52 of whom fulfilled Garcia's criteria and were selected for the study. Survival analyses were performed to determine whether survival differences were of statistical significance, and P < 0.05 was considered as significant.

RESULTS

Malignant transformation is characterized by a rapid onset of symptoms, recurrence, leptomeningeal carcinomatosis (LC), and tumor enhancement at Computed Tomography Scan or Magnetic Resonance Imaging (87.8 showed this radiological feature). In this review, the SCCs were classified in five groups: (1) Initial malignant transformation of a benign cyst; (2) malignant transformation from a remnant cyst; (3) malignant transformation of a dermoid and epithelial cyst; (4) malignant transformation with leptomeningeal carcinomatosis; (5) other malignancies arising from benign cysts. The median survival was 9 months. Statistics show that LC was of poor prognosis and radiotherapy, although not statistically significant, seems effective against such lesions, with a median survival of 26 months as opposed to 3 months (P=0.077).

CONCLUSION

Although rare, malignant transformation of intracranial epithelial cysts has a poor prognosis and surgery followed by radiotherapy seems to be the best therapeutic modality.

Far-lateral transcondylar approach: surgical technique and its application in neurenteric cysts of the cervicomedullary junction

Neurenteric cysts are rare benign lesions of the central nervous system that are lined by endodermal cell–derived epithelium. Although they occur mostly in the spine, they can occur intracranially, most often in the posterior fossa. Neurenteric cysts that are located in the anterior cervicomedullary junction are even rarer and often require a skull base approach for adequate resection. The authors describe two cases of neurenteric cysts arising from the cervicomedullary junction that were resected via a far-lateral transcondylar approach. They discuss the surgical approach and operative nuances involved in removing these lesions, and review the clinical presentation of neurenteric cysts in this region as well as the neuroimaging characteristics, histopathological findings, and surgical management. Intraoperative videos are presented.