Multiple intracranial enterogenous cysts

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.

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.

Recurrent Lateral Ventricular Enterogenous Cyst: A Report of an Extreme Rare Case

The patient was a 45-year-old man with a progressive headache. Evaluation in detail revealed it as a case of left lateral ventricular space occupying lesion (SOL) resembling choroid plexus papilloma. A left parietal craniotomy was done and the lesion was removed completely through intraparietal approach. Surgical removal resulted in complete symptomatic relief. Histopathology revealed that it was a case of the enterogenous cyst. One year after surgery, the patient again experienced the same symptom and the images revealed recurrence of the lesion. The patient has undergone 2nd surgery and histopathology was the same as before. The patient was given radiotherapy and now he is completely relieved and well. Although intracranial enterogenous cyst is not uncommon, intraventricular enterogenous cyst as well as recurrent intraventricular enterogenous cyst is a rare entity.

Intraparenchymal Supratentorial Neurenteric Cyst

Background:

Neurenteric cysts are congenital cysts of the central nervous system that are believed to be of endodermal origin. In this report we present the unique case of a supratentorial neurenteric cyst that is contained entirely within the brain parenchyma.

Methods:

Apatient presented with an intraparenchymal cystic lesion that was subsequently identified as a neurenteric cyst. This lesion is reviewed in light of the available literature.

Case report:

A 35-year-old female presented with a one year history of progressive headaches and seizure-like episodes. Her examination revealed no deficits. Magnetic resonance imaging showed a 4 cm x 4 cm x 4 cm cystic lesion within the parenchyma of the right frontal lobe. A right frontal craniotomy and complete excision of the cystic lesion was performed. Pathologic examination confirmed that it was a neurenteric cyst. Postoperatively the patient's symptoms improved.

Conclusion:

Review of the literature revealed this to be the first case of a surgically excised, pathologically confirmed supratentorial neurenteric cyst, contained entirely within the brain parenchyma.

Supratentorial neurenteric cyst mimicking hydatid cyst: A case report and literature review

Neurenteric (NE) cysts are uncommon congenital cysts of endodermal origin. These cysts are commonly encountered in the posterior fossa surrounding the brain stem structures. We present a case of pathologically proven supratentorial NE cyst that mimicked a hydatid cyst in its clinical presentation and imaging appearance. Including this pathology in the differential diagnosis of supratentorial cystic lesions is important due to the differences in medical and surgical management.

Neurenteric cysts of the spine

Neurenteric cysts account for 0.7-1.3% of spinal axis tumors. These rare lesions result from the inappropriate partitioning of the embryonic notochordal plate and presumptive endoderm during the third week of human development. Heterotopic rests of epithelium reminiscent of gastrointestinal and respiratory tissue lead to eventual formation of compressive cystic lesions of the pediatric and adult spine. Histopathological analysis of neurenteric tissue reveals a highly characteristic structure of columnar or cuboidal epithelium with or without cilia and mucus globules. Patients with symptomatic neurenteric cysts typically present in the second and third decades of life with size-dependent myelopathic and/or radicular signs. Magnetic resonance imaging and computed tomography are essential diagnostic tools for the delineation of cyst form and overlying osseous architecture. A variety of approaches have been employed in the treatment of neurenteric cysts each with a goal of total surgical resection. Although long-term outcome analyses are limited, data available indicate that surgical intervention in the case of neurenteric cysts results in a high frequency of resolution of neurological deficit with minimal morbidity. However, recurrence rates as high as 37% have been reported with incomplete resection secondary to factors such as cyst adhesion to surrounding structure and unclear dissection planes. Here we present a systematic review of English language literature from January 1966 to December 2009 utilizing MEDLINE with the following search terminology: neurenteric cyst, enterogenous cyst, spinal cord tumor, spinal dysraphism, intraspinal cyst, intramedullary cyst, and intradural cyst. In addition, the references of publications returned from the MEDLINE search criteria were surveyed in order to examine other pertinent reports.

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.

Multiple neuroenteric cysts at cerebello-pontine angle and foramen magnum: a case report and review of the literature

Neuroenteric cysts of the CNS are uncommon benign lesions usually involving the spinal cord or rarely the cerebellopontine angle (CPA). We report a rare example of multiple neuroenteric cysts arising from the CPA and foramen magnum in a 20-year-old Caucasian woman who presented with headaches and dizziness. An MRI showed three separate lesions, not communicating with each other. The first lesion, within the left posterior lateral aspect of the CPA, demonstrated isointensity to gray matter on the fluid-attenuated inversion recovery (FLAIR) sequence. The second lesion, within the left foramen of Luschka at the level of the CPA, demonstrated hyperintensity on the T(2)-weighted sequences, intermediate to slightly hyperintense on T(1)-weighted sequence and hyperintensity on FLAIR. The third lesion, within the anterior/inferior left cerebellum at the level of the foramen magnum, followed CSF signal intensity throughout. None of the lesions demonstrated significant enhancement or bone lesions. Due to compression effect, surgery was performed. Pathologic examination revealed cystic structures lined by a single layer of non-ciliated well-differentiated mucin-producing columnar epithelium with eosinophilic to amphophilic cytoplasm and round to oval nuclei with focal pseudostratification. Immunohistochemical studies showed focal positivity for cytokeratin 7, CK 5/6, synaptophysin, and carcinoembryonic antigen (CEA), diffuse positive staining for epithelial membrane antigen (EMA) and BerEP4; and negative staining for cytokeratin 20, TTF-1, and GFAP. The MIB-1 proliferation index was < 1%. One-year follow-up has shown no recurrence. The differential diagnosis and a brief review of the literature are also presented.

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.

NEURENTERIC CYST ARISING IN THE HIGH CONVEXITY PARIETAL LESION

OBJECTIVE

Supratentorial neurenteric cysts (NC) are rare; only 16 cases were reported previously, the majority of which were located in the anterior fossa or in the deep midline structure. We report a case of NC arising in the high convexity parietal lesion and briefly discuss the histogenesis of NC in such an unusual location.

CLINICAL PRESENTATION

A 63-year-old man presented with a 1-month history of progressive headache and dizziness. Computed tomographic and magnetic resonance imaging scans demonstrated a 4 × 5 × 5 cm extra-axial cystic lesion in the right parietal convexity adjacent to the sagittal sinus without contrast enhancement. A translucent thin-walled cyst containing a milky-white fluid was partially excised via a right parietal craniotomy.

INTERVENTION

The cyst wall was composed of a thin fibroconnective tissue lined by a single layer of ciliated columnar epithelial cells and pseudostratified columnar epithelium. Mucous-secreting goblet cells of epithelial lining reacted to periodic acid-Shiff staining. The internal epithelial cells were immunoreactive to cytokeratin and epithelial membrane antigen, but not to carcinoembryonic antigen, glial fibrillary acidic protein, or S-100 protein. A follow-up magnetic resonance imaging scan taken 6 months later showed resolution of mass effect without evidence of cyst recurrence. The patient was discharged home in excellent condition.

CONCLUSION

A case of NC arising in the high convexity parietal lesion is described. Supratentorial NCs located far from the location of the primitive endoderm suggest the possibility that NCs could arise from ectopic endodermal tissue through an undetermined process of anomalous differentiation. Total surgical excision of the cyst wall and contents is the best treatment for the symptomatic cases. Subtotal or partial resection without injury to important neurovascular structures are reasonable alternatives, but long-term careful follow-up magnetic resonance imaging or computed tomography is necessary to monitor for recurrence of any residual lesion.

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.

Giant Supratentorial Enterogenous Cyst: Report of a Case, Literature Review, and Discussion of Pathogenesis

OBJECTIVE AND IMPORTANCE

To describe a histologically well-documented adult case of a giant supratentorial enterogenous cyst (EC). Fewer than 15 cases of supratentorial ECs are on record: 8 associated with the brain hemispheres or the overlying meninges, 4 with the sellar region, and 2 with the optic nerve.

CLINICAL PRESENTATION

A 31-year-old woman complained of long-standing mild left brachial and crural motor deficit precipitated by headache and signs of intracranial hypertension. Magnetic resonance imaging revealed a huge cyst overlying the frontoparietal brain.

INTERVENTION

Symptoms were relieved by evacuation of the cyst content by means of a Rickam's reservoir, and the lesion was subsequently removed in toto. Histological and immunohistochemical examination of the cyst wall clearly established the enterogenous nature of its epithelium. Follow-up for up to 2 years after intervention showed no sign of recurrence, and symptoms, including treatment-resistant seizures in the postoperative period, have entirely subsided.

CONCLUSION

Supratentorial ECs, distinctly rare in adult patients, may in some cases present as giant lesions. Total removal seems to be curative once careful examination has eliminated the possibility of a metastasis from an unknown primary. A correct histological diagnosis is important because, in contrast to other benign cysts of similar location and size, ECs may be prone to intraoperative dissemination.

Intrapontomesencephalic colloid cyst: an unusual location. Case report

Colloid cysts appear most commonly in the third ventricle; the occurrence of a colloid cyst in the brainstem is very unusual. The authors report on a patient with an intrapontomesencephalic colloid cyst. This 15-year-old girl complained of a headache associated with diplopia. Her neurological examination revealed right-sided sixth nerve paresis and a mild left hemiparesis. Radiological investigations revealed an intraparenchymal pontomesencephalic cystic mass. Surgical removal of the lesion was achieved via the pterional transsylvian approach and the patient experienced an excellent recovery. Histopathological examination revealed that the lesion was a typical colloid cyst. To the best of the authors' knowledge, this is the first case in which an intraparenchymal upper brainstem colloid cyst was surgically excised totally. In addition to describing this case, the authors also review other brainstem neuroepithelial cysts described in the literature and briefly discuss the concept of their origin.

Neurenteric cyst of the craniocervical junction. Report of three cases

Neurenteric cysts of the craniocervical junction (CCJ) are very rare lesions. Their origin is the subject of long-standing controversy, but a failure during the embryogenic phase may be responsible for their formation. Accurate histopathological diagnosis may be difficult due to the similarity they share with other cystic lesions such as colloidal cysts, Rathke cysts, and cystic teratomas. Surgical removal is the treatment of choice for intracranial neurenteric cysts, but in some cases, infiltration of the surrounding structures may hinder complete resection. Three cases of neurenteric cysts located at the CCJ are reported.

Posterior fossa epithelial cyst: case report and review of the literature

A 49-year old woman with progressive cranial nerve signs and hemiparesis was found at MR imaging and at surgery to have a cyst at the foramen magnum. Immunohistochemistry and electron microscopy showed an epithelial cyst of endodermal origin. MR findings were of an extraaxial mass, with short T1 and T2 times. Unless immunohistochemistry and electron microscopy are used in the final diagnosis of such cysts, all posterior fossa cysts lined by a single layer of epithelium should be described simply as epithelial cysts.

Aggressive enterogenous cyst with extensive craniospinal spread: case report

OBJECTIVE AND IMPORTANCE

Considered benign and malformative in nature, enterogenous cysts are predominantly spinal lesions. Although recurrences have been reported, especially in the rare intracranial examples, craniospinal dissemination has never been described.

CLINICAL PRESENTATION

We report a 63-year-old woman who presented 16 years previously with a histologically typical enterogenous cyst of the cerebellum. Fourteen years after its incomplete excision, numerous supratentorial, infratentorial, and spinal subarachnoid cysts were detected. A histological examination revealed multiple enterogenous cysts without evidence of malignancy. Ki-67 (MIB-1) proliferative indices were less than 1% in all except one specimen, wherein it was 4%; immunohistochemistry demonstrated rare p53 protein overexpression.

INTERVENTION

During the last 2 years, four subtotal resections of spinal enterogenous cysts have been performed for progressive paraplegia, pain, paresthesia, and bladder dysfunction. Considering the multiple recurrences and progressive neurological deficits, craniospinal radiation therapy was given.

CONCLUSION

To our knowledge, this is the first report of widespread craniospinal dissemination associated with the incomplete resection of an enterogenous cyst. Although a rare complication, it emphasizes the advantages of early, aggressive surgery.

Well-differentiated papillary adenocarcinoma arising in a supratentorial enterogenous cyst: case report

OBJECTIVE AND IMPORTANCE

We report a case of a well-differentiated papillary adenocarcinoma arising in an supratentorial enterogenous cyst. The clinicopathological features of this case and a brief review of the literature are presented.

CLINICAL PRESENTATION

A 45-year-old woman presented with abrupt onset of sensory seizures and abnormal sensation on the left side of her face, left leg, and left arm. Radiological studies showed a cystic extraaxial tumor with mass effect in the right parietal area. The initial clinical impression was a metastatic lesion, and a comprehensive metastatic workup revealed no evidence of tumor elsewhere.

INTERVENTION

A gross total resection of the solid cystic tumor was achieved by a frontoparietal craniotomy. Sixteen months after the initial surgery, the patient presented with signs of increased intracranial pressure and a large parietal cyst. The cyst was fenestrated at the time of the second craniotomy.

CONCLUSION

A pathological study of the initial surgical material revealed it to be a well-differentiated papillary adenocarcinoma in association with an enterogenous cyst. The second surgical specimen consisted only of the benign cyst wall. The patient recovered uneventfully from the second surgery and was free of symptoms 6 months postoperatively. The importance of recognizing the rare possibility of malignant progression of a benign enterogenous cyst in the central nervous system is discussed.

Endodermal cysts of the posterior fossa. Report of three cases and review of the literature

The pathogenesis of endodermal cysts of the posterior fossa is still incompletely understood. The authors reviewed three new cases and those reported in the literature to clarify the clinical, pathological, radiological, and surgical characteristics of these lesions. A total of 49 cases were reviewed. Details on demographic profiles, clinical characteristics, histopathological and radiological features, and surgical methods were collected. These cysts have a predominance in male patients (61%) and can occur at any age (birth-77 years). In patients with posterior fossa endodermal cysts there is a bimodal age distribution and headache is the most frequent complaint. On immunohistopathological examination, endodermal cysts were reactive for epithelial membrane antigen and for keratin immunostains whenever the latter were tested. The cysts were reactive for carcinoembryonic antigen in nine of 11 cases. Endodermal cysts were located anterior to the brainstem in 51% of cases and in the fourth ventricle in 21% of cases. They frequently appeared hypodense on computerized tomography scans, and in five cases, the lesion was missed. The cyst's appearance on magnetic resonance imaging is variable. Resection was complete in 19 cases and partial in 11; marsupialization was achieved in two cases. Three recurrences have been reported. Total excision with preservation of neurological function should be the goal. Cranial base approaches are helpful for surgical access in selected examples of these lesions.

Fine-needle aspiration diagnosis of enterogenous cyst of the orbit: a case report

Enterogenous cyst is a benign lesion derived from misplaced endodermal epithelium. We report the aspiration cytology findings of an orbital cyst from a 32-year-old woman. The smears contain benign-appearing cuboidal glandular cells with focal mucinous features. Carcinoembryonic antigen level in the cyst fluid was markedly elevated. These findings are consistent with recurrence of the enterogenous cyst initially diagnosed 7 years earlier.

Craniospinal and spinal enterogenous cysts--report of three cases

We report three cases of enterogenous cyst, one craniospinal and two spinal manifesting with features of spinal cord compression. In one the cyst was intramedullary in location and in the other two it was intradural, extramedullary. The unusual clinical presentation, location and magnetic resonance imaging (MRI) characteristics are discussed. None of the three patients had any vertebral anomaly or other congenital malformation. All patients had excellent outcome following surgery.

Do the suprasellar neurenteric cyst, the Rathke cleft cyst and the colloid cyst constitute a same entity?

Two cases of entirely suprasellar cysts are reported. Total surgical removal was performed in both cases. Pathological and immunohistochemical profiles were consistent with neurenteric cysts, Rathke's cleft cysts or colloid cysts and was also in keeping with an endodermal origin. It is now admitted that these three kinds of cysts share similar histological and immunohistological features. We propose an hypothesis of common embryological origin from endodermal remnants.

Enterogenous cyst of the orbital apex and superior orbital fissure

BACKGROUND

Enterogenous cysts of the central nervous system are rare congenital tumors with a single layer of mucin-secreting epithelial cells resembling gastrointestinal epithelium. The tumor is located most commonly at lower cervical and cervicothoracic spinal levels; only 22 intracranial cases have been reported. To the authors knowledge, this entity has not been described in the orbit.

METHODS

A 23-year-old woman with painful loss of vision and ophthalmoplegia in the left eye was treated with oral and intravenous corticosteroids for presumed orbital inflammation. After a cystic lesion in the left orbital apex was demonstrated on computed tomographic scan and magnetic resonance imaging, various diagnoses, including optic nerve tumor, granulomatous inflammation, lymphoma, vascular anomaly, and pseudotumor, were considered until transcranial biopsy established the correct diagnosis. The tumor subsequently recurred twice.

RESULTS

More than 3 years after the last recurrence, the patient has no pain but had unilateral optic atrophy, significant visual field loss, limited motility, and an anesthetic cornea in the left eye.

CONCLUSION

The diagnosis of enterogenous cyst is difficult without adequate biopsy because the radiologic and clinical presentation of this rare tumor may be confused with other lesions. Previous attempts to explain intracranially placed enterogenous cysts offer no explanation for an orbital occurrence nor do they adequately describe a mechanism for an intracranial location in general. An embryologically based explanation that takes into account the occurrence of this entity from the caudal to rostral extent of the neuraxis is described. This theory suggests that the orbit is the most rostral possible location for an enterogenous cyst.

An epithelial cyst of the suprasellar region

A case of a 26 year old woman with increasing headaches due to a suprasellar cyst is described. Histology was consistent with an epithelial cyst with features resembling both Rathke's cleft cysts and enterogenous cysts. The differential diagnosis and treatment of suprasellar cysts is discussed.

Compressão medular alta por cisto neuroentérico: relato de caso

É relatado o caso raro de uma criança com cisto neuroentérico comprimindo a medula cervical alta de C1 a C3. A paciente foi submetida a laminectomia osteoplástica com retirada total do tumor. São discutidos a sintomatologia, o tratamento e o resultado satisfatório obtido. É feita revisão da literatura pertinente.

Colloid cyst of the third ventricle. A comparative immunohistochemical study of neuraxis cysts and choroid plexus epithelium

In an effort to shed light upon the nature of the colloid cyst, the immunohistochemical properties of 21 examples of this lesion were compared with those of other neuraxial cysts and choroid plexus epithelium. The neuraxial cysts included the following: eight Rathke's cleft cysts, 25 pituitaries containing follicular cysts of the pars intermedia, and four enterogenous cysts. Fifteen examples of normal choroid plexus and 12 choroid plexus papillomas were studied as well. These lesions were examined for localization of the following antigens: cytokeratins, epithelial membrane antigen, secretory component, carcinoembryonic antigen, prealbumin, vimentin, glial fibrillary acidic protein (GFAP), S-100 protein, neuron-specific enolase, 68-kD neurofilament protein, chromogranin, serotonin, and lysozyme, and with Leu-7 monoclonal antibodies. Five colloid cysts were immunostained with monoclonal antibodies that were specific for Clara-cell antigens and surfactant, respectively. Sugar moieties were localized using Ulex europaeus I, and Ricinus communis agglutinin I lectins. All Rathke's cleft cysts and follicular cysts of the pars intermedia as well as three selected colloid cysts were examined for pituitary hormones. The epithelial cells of colloid and enterogenous cysts, as well as those lining follicular and Rathke's cleft cyst, showed uniformly strong reactivity for cytokeratins, epithelial membrane antigen, secretory component, and vimentin, and bound Ulex europaeus lectin. Occasional cells in colloid cysts were positive for Clara cell-specific antigens. Reaction for carcinoembryonic antigen was present on the apical surface of scattered cells of colloid, follicular, and Rathke's cleft cysts. Many cells of follicles in the pars intermedia as well as individual cells of five Rathke's cleft cysts were also immunoreactive for chromogranin, S-100 protein, GFAP, and pituitary hormones. Colloid and enterogenous cysts were negative for prealbumin, S-100 protein, GFAP, and neuron-specific enolase; in all but a few instances, they failed to bind Ricinus communis agglutinin. In contrast, normal choroid plexus and choroid plexus papillomas were positive for prealbumin, S-100 protein, neuron-specific enolase, cytokeratin, vimentin, and Ricinus communis agglutinin receptors; they lacked Ulex europaeus lectin, 56/66-kD cytokeratins, and epithelial membrane antigen. Unlike normal choroid plexus, choroid plexus papillomas were often GFAP-positive. All tissues studied were nonreactive for lysosome, serotonin, and neurofilament, and with Leu-7 antibodies. This study indicates that the immunophenotype of epithelium lining colloid cysts is similar to that of other cysts showing endodermal or ectodermal differentiation and to respiratory tract mucosa. Epithelium of colloid cysts is immunohistochemically different from that of normal or neoplastic choroid plexus. These findings indicate an endodermal rather than neuroepithelial nature for colloid cysts.

Colloid cyst of the third ventricle: a comparative ultrastructural study of neuraxis cysts and choroid plexus epithelium

Thirteen colloid cysts (CC), four Rathke cleft cysts (RCC), three follicular cysts of normal pituitary gland (FCP), four enterogenous cysts (EC), three normal choroid plexi (CP), three choroid plexus papillomas (CPP), and several samples of normal bronchial mucosa and ependyma were studied by electron microscopy. The ultrastructure of most of the CC was indistinguishable from that of RCC, FCP, EC, and normal bronchial mucosa in demonstrating nonciliated and ciliated epithelial cells, goblet cells, basal cells, and intermediate forms, some showing evidence of early squamous differentiation. Two CC displayed mostly squamous differentiation, and one contained basally situated cells resembling myoepithelial cells. Although the RCC and FCP displayed features similar to those of CC, they also contained cells with electron-dense granules indicating pituitary hormone production and scattered cells showing oncocytic change. EC were lined by either squamous cells or mucin-producing columnar cells. Every CC, RCC, FCP, and EC contained cells covered by glycocalyx. In contrast to aforementioned lesions, ependymal lining, CP, and CPP were composed of a single cell type, one with numerous villi, few cilia, and no signs of keratinization, mucin production, or glycocalyx coating. It is concluded that the ultrastructural properties of CC are the same as those of cysts of endodermal or ectodermal origin and of respiratory mucosa. No ultrastructural similarities were observed between CC and normal or neoplastic neuroepithelium. These ultrastructural findings support the concept of an enterogenous origin of colloid cysts and highlight their similarity to RCC.

Enterogenous cyst at the cerebellopontine angle: case report

A case of enterogenous cyst at the cerebellopontine (CP) angle is reported. A review of the literature yielded only seven cases of intracranial enterogenous cysts, and our case is the first one arising at the CP angle. The histological features, pathogenesis, and radiological and auditory brain stem response findings are discussed.

Albucasis or Abul Kasim (936-1013)

Images

Cysts of the neuraxis of endodermal origin

Five colloid cysts of the third ventricle were compared with two spinal enterogenous cysts to examine the hypothesis that these entities have the same origin from primitive endodermal tissue. All the lesions showed cuboidal and columnar epithelium with mucus containing goblet cells and cilia. Immunohistochemistry for cytokeratin, EMA and CEA was positive in all the colloid cyst and enterogenous cyst epithelium. S-100 was focally positive in three of the colloid and one of the enterogenous cysts while vimentin and GFAP were negative in both. The anatomical distribution of both colloid and enterogenous cysts is reviewed. An illustrative case of an identical cyst within the fourth ventricle is presented. This suggests that the similarities between colloid and enterogenous cysts and the presence of identical lesions along the neuroaxis indicate that these structures are derived from primitive foregut endoderm.

An epithelial cyst in the cerebellopontine angle. Case report

A case of a benign epithelial cyst in the posterior cranial fossa is described. It had the unique histological feature of a double-layered cuboidal epithelial lining. Detailed immunohistochemical and electron microscopic studies supported an endodermal origin. The differential diagnosis and the histogenesis of epithelial cysts in the central nervous system are discussed.

Craniospinal neurenteric cyst

The case of a 40-year-old male with a neurenteric cyst located anterior to the brain stem and to the C1-C2 levels of the spinal cord is presented. The cyst was successfully removed by a transoral approach. The case is discussed and literature reviewed.

Intraparenchymal epithelial (enterogenous) cyst of the medulla oblongata

Intraparenchymal solitary cyst of the medulla oblongata was diagnosed on MRI examination in a 66-year-old woman with a nine year history of progressive brainstem dysfunction and three negative CT scan examinations. Craniotomy and drainage of the cyst to the IVth ventricle led to remarkable clinical recovery. Biopsy of the wall of the cyst revealed an epithelial lining with tonofilaments, desmosomes and surface coating on ultrastructural examination. Immunohistochemistry demonstrated positive reactions of epithelium for keratins, cytokeratins, epithelial membrane antigen and Ulex Europeus lectin, indicating endodermal origin of the cyst.