An epithelial cyst in the cerebellopontine angle. Case report

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.

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.

Enterogenous cysts of the cerebellopontine angle: short review illustrated by two new patients

Intracranial enterogenous cysts are an uncommon entity rarely found in the midline within the posterior cranial fossa. The occurrence of an enterogenous cyst in the cerebellopontine angle is exceptional. We present two new cases of cerebellopontine angle (CPA) enterogenous cysts and review the literature to clarify the diagnosis and the management of these lesions. Eighteen cases of CPA intradural enterogenous cysts have been reported to date, including the two cases presented in this article. All of them were symptomatic and underwent surgical treatment. After surgery, the symptomatic recurrence occurred in 31% of the patients, most of which had partial excision. Considering our patients and the published cases in the literature we suggest that the aim of surgery should be total removal of cyst and its content whenever possible. When partial resection of the cyst is performed, we recommend long-term clinical and neuroradiological follow-up.

Enterogenous cysts of the spinal canal and cerebellopontine angle

Enterogenous cysts are rare, benign lesions involving the spinal canal or the cerebellopontine angle. Typically they present with compression of the spinal cord or cranial nerves. They are usually 1 cm or less in size and are typically lined by columnar mucin-producing epithelium resembling enteric epithelium or columnar ciliated epithelium resembling respiratory epithelium. The case records of the Division of Neuropathology at Indiana University were reviewed for cystic lesions of the spinal canal and cranial cavity for a 26-year period. Seven surgically resected enterogenous cysts were identified. The original slides were studied. Additional sections were stained with mucicarmine, and immunohistochemical stains including thyroid transcription factor 1, epithelial membrane antigen, and cytokeratin 5/6 (CK5/6) were performed. Electron microscopy was performed in 1 case. The cysts ranged in size from 4 to 10 mm. One had stratified cuboidal epithelium, 1 had ciliated columnar and stratified squamous epithelium, 1 had columnar mucinous epithelium, and 4 had ciliated columnar epithelium. Epithelial membrane antigen and CK5/6 positivity were observed in all cases. Strong CK5/6 positivity was seen in the basal cells, with little or no immunoreactivity in the ciliated cells. Mucicarmine positivity was observed in 4 cases, and thyroid transcription factor 1 positivity was observed in 2 cases. Electron microscopy demonstrated well-developed stereocilia, distinct basal cells, and a thin basement membrane. The histopathologic, ultrastructural, and immunologic findings in these lesions are similar to those present in the bronchial epithelium, supporting the hypothesis of endodermal origin for these lesions.

Extradural neurenteric cyst of the cerebellopontine angle

✓ Neurenteric cyst is a developmental malformation found mainly in the spinal canal. The authors report on a 47-year-old man with a neurenteric cyst of the cerebellopontine angle (CPA) who presented with progressive hearing disturbance and facial palsy. The tumor was located extradurally with marked destruction of the petrous bone around the internal auditory canal and demonstrated irregular and heterogeneous high-intensity signals on T1- and T2-weighted on MR images, which is atypical for neurenteric cysts. The pathological findings in samples obtained after resection disclosed a single epithelial layer (a feature of neurenteric cyst), which was accompanied by marked xanthogranulomatous changes. Although several neurenteric cysts have been reported in the CPA, extradural lesions with unusual imaging features and marked bone destruction have not been reported previously. This benign developmental lesion should be considered, although it is extremely rare, in patients harboring an extradural temporal bone tumor around the CPA.

Intraepithelial carcinoma arising in an endodermal cyst of the posterior fossa

Endodermal cysts of the central neuraxis are benign, non-neoplastic epithelium-lined cysts arising from endodermal tissue that have been displaced early in fetal life. Intracranial endodermal cysts are rare and usually located in the posterior fossa. The present study involves a 36-year-old man with a typical epithelial cyst in the posterior fossa. Microscopically, the cyst has a simple columnar epithelium with mucus-producing cells, containing an area composed of dysplastic epithelium with evidence of an intraepithelial carcinoma. The atypical cells have a high proliferative fraction demonstrated by Ki-67 immunostain. Based on these findings, the authors view this case as evidence of a malignant transformation of a classic endodermal cyst. The clinicopathologic features and a review of the literature are discussed.

Neuroepithelial cysts of the middle ear

Neuroepithelial cysts are lesions of the central nervous system that have previously been reported in cerebral parenchyma, in the spinal cord, and within the ventricles in association with the choroid plexus. We describe 2 cases of neuroepithelial cysts of the middle ear. One was diagnosed after surgery for a retraction pocket and chronic otitis media complicated by an intraoperative cerebrospinal fluid (CSF) leak. The other produced bilateral spontaneous CSF otorrhea and mimicked the presentation of arachnoid granulations. Both cases were verified with immunohistochemical stains. Neuroepithelial cysts, although rare, should be considered in the differential diagnosis of spontaneous CSF otorrhea or an epitympanic mass.

Neurenteric cyst of the cerebellopontine angle: case report

OBJECTIVE AND IMPORTANCE

We report a case of a neurenteric cyst of the cerebellopontine angle and review the five previously reported cases. The pathology and classification of these cysts are discussed.

CLINICAL PRESENTATION

The patient presented with a 1-month history of nausea, vomiting, vertigo, and sudden hearing loss.

INTERVENTION

The cyst was decompressed by a retrosigmoid approach. After recurrence of symptoms at 2 months, further decompression was required.

CONCLUSION

The patient achieved a good outcome after the second operation, with cessation of her vomiting and vertigo, although she had residual hearing loss. Four of the five previously reported patients experienced satisfactory outcomes after surgery. The definitive diagnosis of these rare lesions is made using immunocytochemical techniques.

Glioependymal cyst of the cerebellopontine angle

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Cerebellopontine angle epithelial cyst. A case report

A case of epithelial cyst in the cerebellopontine angle is reported. The cyst wall showed glandular epithelium with areas of non-keratinized stratified epithelium and flattened cuboidal cells. The glandular areas stained positively with antibodies to cytokeratin. In addition, the cyst wall contained areas of arachnoid tissue. This, and the unusual position of the cyst, suggest that the epithelial elements in the cyst wall may be metaplastic in origin. Similar previously described cysts were considered to be endodermal in origin.