Cisto epidermoide da fossa posterior: relato de caso / Epidermoid cyst of the posterior fossa: a case report

Epidermoid cysts of the central nervous system are uncommon conditions, which are frequently located in the cerebellopontine angle and around the pons. They are covered with keratinized squamous epithelium and keratin lamella, which give its contents a soft, white-pearly appearance. Epidermoid cysts are mostly originated from malformations, presumably associated with surface elements of the nervous system ectoderm during the closure of the neural groove or formation of secondary cerebral vesicles. The authors describe a case of epidermoid cyst in the posterior fossa causing hydrocephalus and review morphologic and diagnostic criteria of this lesion.

Os cistos epidermoides do sistema nervoso central (SNC) são condições incomuns, estando localizados mais frequentemente no ângulo pontocerebelar e ao redor da ponte. Eles são revestidos por epitélio escamoso queratinizado e lamelas de queratina, tornando seu conteúdo branco-perolado e pastoso. Os cistos epidermoides são, na maioria das vezes, originados de malformações, possivelmente associados ao entremeio de elementos superficiais do ectoderma do SNC durante o fechamento da placa neural, ou formação das vesículas cerebrais secundárias. Os autores descrevem um caso de cisto epidermoide da fossa posterior determinando hidrocefalia e revisam critérios morfológicos e diagnósticos dessa lesão.

overview in stereotactic radiosurgery

Efficacy and utilization of radiation as a mode of management in neurosurgical lesions has increased radically as a consequence of improvements in appreciation of the concept of stereotaxis, progress in medical imaging, computer technology, and advanced delivery devises. [19.22] Primary management alternative in patients with cerebellopontine angle lesions, skull base tumours, meningiomas, paragangliomas, AVMs etc., is increasingly being used as also in secondary management of recurrent or planned residual disease patients where a part of the lesion is deliberately left behind to avoid loss of function and prevent iatrogenic injury. [22] Contemporary understanding with adequate and proper information of this resource along with understanding the controversies regarding the use of radiation of the management of several lesions in paramount. This article is intended to provide a concise basic introduction of the technology available and the pertinent applications in the management for several lesions with a basic understanding of the advantages and disadvantages of various available devices and the outcome in using various methods based on review of available literature

Tuberculoma as expansive process of the cerebellopontine angle; A rare presentation

Central nervous system tubrculoma presenting as a solitary mass in an extrinsic location is rare. Many factors make the diagnosis difficult, necessitating a surgical procedure. A 24-year-old man complained of unstable gait, slurred speech and occipital headache. Examination revealed an alert individual with bilateral horizontal nystagmus, facial palsy in the left and gait ataxia. Radiological investigation showed a growing process in the left cerebellopontine angle. Partial removal of the lesion via a retromastoid sub-occipital craniotomy approach revealed tuberculoma. Antituberculous treatment led to complete resolution of symptoms. This report shows that a mass in the CP angle can closely mimic a tumour radiologically. Histophathological examination confirmed it to be tuberculoma. Awareness of this rare presentation of a solitary tuberculoma in the CP angle is emphasized

Cystic acoustic schwannoma: a case report and review of literature

A cystic acoustic neurinoma almost entirely consists of a cystic component and is a well recognized subtype of acoustic schwannoma. We report a case of a 40-yearold male patient who presented with clinical features of a left cerebello-pontine angle mass lesion and CT scan findings mimicking the diagnosis of an epidermoid cyst. However intraoperative and histopathological findings were suggestive of a large cystic acoustic schwannoma. We have also analyzed the characteristics, clinical symptoms and radiological findings of these tumors. In the presence of a large cystic cerebellopontine angle tumor without a significant hearing loss and no destruction of the internal auditory canal, the possibility of the cystic acoustic neurinoma should be considered

Associação entre tamanho e potencial proliferativo em neurinomas do acústico / Size and proliferative index correlation in acoustic neuromas

Schwanomas do acústico são os tumores mais freqüentes localizados no ângulo pontocerebelar. Os mecanismos moleculares que levam a sua geração e crescimento ainda não são bem conhecidos. Várias características clínicas, radiológicas e imuno-histoquímicas já foram estudadas e correlacionadas ao crescimento tumoral. Estudamos e correlacionamos aspectos clínicos e imuno-histoquímicos (MIB-1) de 11 schwanomas do acústico operados no Hospital São Paulo/UNIFESP. O tamanho dos tumores correlacionou-se com o índice proliferativo (Ki-67), não havendo correlação com significância estatística entre a idade dos pacientes, duração dos sintomas e índice proliferativo.

A Case of Medullomyoblastoma of Cerebellopontine Angle Mimicking Acoustic Neuroma

Medulloblastoma is a common malignant central nervous system neoplasm found mainly in children. One the contrary, medulloblastoma of the cerebellopontine angle, the location of the tumor is very unusual. This is the the first case of the medullomyoblastoma, a rare form of medulloblastoma, occurring in the cerebellopontine angle. A 15-year-old boy experienced a sudden hearing loss in the left ear. Conservative medical treatment failed, and temporal MR imaging revealed a heterogeneously enhancing mass at the left cerebellopontine angle cistern and in the internal auditory canal; therefore, the lesion was regarded as a typical acoustic neuroma. Few days before surgery, an ipsilateral facial palsy developed, and a follow-up MR imaging showed a rapid growth of the previous lesion. The extended translabyrinthine approach permitted surgical removal. And under pathological diagnosis of malignancy, radiation therapy and series of chemotherapy was performed.

Lipoma in the region of the jugular foramen.

A 22-year-old girl presented with a gradually progressive loss of hearing in the left ear and ipsilateral facial paresis. Investigations revealed a lipoma in the region of the jugular foramen. Conservative resection of the tumor resulted in improvement in facial paresis. The treatment options in such cases are discussed in this report.

A hypothesis of epiarachnoidal growth of vestibular schwannoma at the cerebello-pontine angle: surgical importance.

AIMS: The purpose of this study is to clarify the rearrangement of the arachnoid membrane on the vestibular schwannoma during its growth in relation to adjacent neurovascular structures for a better understanding of dissecting plane of arachnoid during surgery. METHODS: Arachnoid membrane over the tumour was investigated during surgery with suboccipital transmeatal approach in twenty-six tumours. All microsurgical procedures were recorded with a video and reviewed. The tumour growth was classified into five stages depending upon the tumour diameter in the cerebello-pontine (CP) angle: Stage 1; purely intracanalicular (2 cases), Stage 2; less than 5 mm (2 cases), Stage 3; > or = 5 and <15 mm (8 cases), Stage 4; > or = 15 and <25 mm (9 cases) and Stage 5; > or = 25 mm (5 cases). Rearrangement of the arachnoid on the tumour was conceptualised throughout all stages. RESULTS: All tumours of Stage 1 and 2 were entirely located in the subarachnoid space of the cerebello-pontine cistern without arachnoidal rearrangement, while all tumours of Stages 3 to 5 were enveloped, in the CP angle, with invaginated arachnoid membrane consisting of cerebello-pontine cistern except two surfaces; the medial pole and the tumour surface under the facial and cochlear nerves near the porus. CONCLUSION: The tumour originates subarachnoidally within the internal auditory meatus (IAM) and grows epiarachnoidally in the CP angle. Rearrangement of the arachnoid begins with its adhesion on the medial pole of the tumour along the porus, resulting in the arachnoidal invagination into the cerebello-pontine cistern with further growing of the tumour.

Choroid plexus papillomas of the cerebellopontine angle.

The cerebellopontine angle (CPA) is a rare site for the growth of choroid plexus papilloma (CPP). The clinicoradiological diagnosis of this tumor in the CPA is difficult because of the nonspecific clinical presentation and radiological features. Five cases of choriod plexus papilloma (3 males, 2 females) operated upon at this center are reviewed. All the cases were operated upon by retromastoid suboccipital craniectomy. As they all presented with a typical CPA syndrome without any distinctive radiological feature, a clinicoradiological diagnosis of CPP could not be reached in any of these. The diagnosis of CPP could only be suspected at the operation table and established on histopathological examination. Two patients developed recurrences at the primary site following surgery. One patient developed recurrence twice despite gross total excision of tumor in each sitting. Subsequently, this patient remained symptom free for a follow-up period of 1 year. Another patient developed recurrence 2 years following surgery, but he died due to septicemia and aspiration pneumonitis. Therefore definitive surgery could not be performed. Radiotherapy was offered to one of the patients having residual mass post operatively, to render her symptom free for a 4 year follow-up. The remaining two patients have also showed progressive improvement in their symptoms following surgery for 4 years on follow-up. Hydrocephalus was a common feature in all the cases preoperatively, but only one required shunt CSF diversion, because of rapid deterioration in visual equity. In all other cases, hydrocephalus was managed conservatively. Surgery remains the main modality of treatment for CPP, both for primary and recurrent tumors, but radiotherapy may have a role in cases of recurrence, which are quite frequent.

Facial nerve neurinoma presenting as middle cranial fossa and cerebellopontine angle mass: a case report.

Facial nerve neurinomas are rare. The tumours arising from the geniculate ganglion may grow anteriorly and superiorly and present as a mass in the middle cranial fossa. Only a few cases of facial nerve neurinomas presenting as middle cranial fossa mass have so far been reported. These tumours present with either long standing or intermittent facial palsy along with cerebellopontine angle syndrome.

Surdez súbita como sintoma. Inicial em tumor de ângulo pontocerebelar / Sudden Deafness like Initial Symptom in Cerebelopontine Angle Tumour

O autor faz uma revisão da literatura sobre surdez súbita e suas principais etiologias. Apresenta um caso clínico no qual este sintoma foi a queixa inicial de um paciente portador de tumor no ângulo pontocerebelar.

The author make a literature revision about sudden deafness and per prime etiology. Show a clinical case when this symptom was the initial complaint of a patient with cerebelopontine angle tumour.

Infratentorial tumours in adults; 2 years study

During the course of two years, 50 adult patients with infratentorial tumours were admitted in our neurosurgical unit at Lahore General Hospital. These were 16.5% of total brain tumours in adults. There were 28 women and 22 men. Most of the patients were from 21 to 50 years of age. Operations were performed in 46 cases. Most of the admissions [45 patients], were through out patient department, and only 5 were through emergency. Commonest symptom was headache [84%] followed by disequilibrium [74%] and visual deficit [72%]. Commonest clinical sign was papilloedema [96%] followed by cranial nerve dysfunction [72%]. Duration of relevant neurological complaints was from 3 months to 2 years. Commonest location was cerebellopontine angle [56%]. Histologically, acoustic neurinoma [52%], metastases [8%] and meningiomas [12%] were the common types. Gross total surgical resection was achieved in 66.6%. Hydrocephalus was present in 84% at presentation. General complications of acoustic neurinoma surgery included CSF leakage in 10%. Total hospital stay has been between 3 to 8 weeks. Radiotherapy was given to 44% of patients. Follow up was possible for only 32% of cases. We did not have a high incidence of metastatic lesions in our patients. We also conclude that intraoperative ventricular tapping and postoperative drainage of CSF is unnecessary and increases the rate of infections; and epilepsy

Management of cerebellopotine angle meningioma

A retrospective study of the surgical management of 114 cerebellopontine angle meningiomas was performed. A combined neurosurgical and otological approach was used for the diagnosis and treatment of acoustic nerve tumors. The evaluation included clinical symptoms, neurological signs, histology, intraoperative findings, early postoperative results and complications. The patients were operated via the suboccipital approach. In cases submitted to a surgical removal of the tumor, there were no operative deaths and all patients were discharged from hospital. In the majority of cases, the cranial nerves were preserved anatomically and functionally. Finally, the results of surgery for cerebellopontine angle meningiomas improved greatly since the introduction of microsurgical techniques

Preservación de la función auditiva en la cirugía de los tumores del conducto auditivo interno y el ángulo pontocerebeloso / Preservation of the auditive function in the tumors surgery of external ear canal and cerebellopontine angle

Las lesiones tumorales a nivel del conducto auditivo interno y el ángulo pontocerebeloso son casi siempre benignas y su predominio está dado primariamente por los neurinomas (schwannomas) del nervio acústico con origen en su rama vestibular, los meningiomas originados en las envolturas meníngeas adyacentes y los colesteatomas provenientes del hueso temporal. Inicialmente, cuando los tumores son pequeños, estos crecen en el conducto auditivo interno y en el espacio real es el ángulo pontocerebeloso, sin dar mayores manifestaciones clínicas. En estas etapas iniciales puede haber o no, pérdidas auditivas moderadas, sensación de inestabilidad corporal y acúfenos. Estos tumores, por ser de poca manigtud, puede pasar desapercibidos para el paciente y peor aún, para el médico quien puede restarle importancia por su poca consistencia. Al crecer estos tumores, los síntomas se hacen evidentes por la compresión neural, terminado en síntomas severos como hipertensión endocraneana, etaxia y muerte. El alto índice de sospecha clínica que conduzca a un diagnóstico precoz, es la base fundamental para la detección temprana de estos tumores. En la actualidad, se cuenta con una batería de pruebas otoneourológicas, tales como el examen audiológico completo y el examen vestibular, destacando la audiometría de tallo cerebral por potenciales evocados, exploración de alta fidelidad para el diagnóstico de una lesión retrococlear. Pero fundamentalmente con la imagen por resonancia magnéctica que permite diagnósticar precozmente lesiones hasta de 2mm de diámetro. El desarrollo de minuciosas técnicas microquirúrgicas a nivel del conducto auditivo interno y ángulo pontocerebeloso, permite hoy en día al otoneurocirujano, abordar quirúrgicamente estos tumores cuando aún no han producido un déficit neurológico significativo y preservar la función cada vez en un mayor porcentaje de casos. El abordaje quirúrgico por la vía de la fosa craneana media y por la vía retrosigmoidea, permiten en la actualidad, preservar la función auditiva al no tocar el oido interno. El rsultado satisfactorio está supeditado a una muy buena selección del caso y al logro de la preservación de la vascularización del oido interno. Este trabajo comenta las exploraciones clínicas más adecuadas para un diagnóstico precoz, las vías de abordaje quirúrgico con sus posibilidades y limitaciones, y analiza las probabilidades de lograr la preservación de la función.

Patología del ángulo pontocerebeloso en el servicio de Neurocirugía del Hospital Regional Honorio Delgado Espinoza

Se realizó un estudio retrospectivo en el Servicio de Neurocirugía del Hospital Regional Honorio Delgado de Arequipa en el periodo comprendido entre enero de 1960 a diciembre de 1996, encontrándose 26 casos de pacientes con lesión del ángulo pontocerebeloso siendo en su totalidad neoplasias, las cuales correspondían al 11.15 por ciento del total de tumores intracraneanos diagnosticados en este periodo en dicho Servicio. La edad máa frecuente de presentación de estas neoplasias oscila entre 20 y 50 años con predominio del sexo masculino sobre el femenino. El agente etiológico encontrado con mayor frecuencia fue el Neurinoma del acústico en 18 casos (69 por ciento); según el cuadro clínico, la mayoría de pacientes se encontraban en la etapa otoneurológica del síndrome del ángulo pontocerebeloso, siendo el signo síntoma más importante la hipoacusia facial. El síndrome de Hipertensión endocraneana se presentó con mayor frecuencia en procesos expansivos que afectaban dicha región en forma secundaria. En cuanto a los exámenes auxiliares utilizados la radiografía simple de cráneo, la cisternografía y la tomografía computada fueron los métodos más precisos para corroborar el diagnóstico.

Primary cerebellopontine angle choroid plexus papilloma: a case report and review of literature.

A case of primary choroid plexus papilloma of the cerebellopontine (CP) angle is described in a 28 years old man. He presented with hearing loss, right facial palsy and spastic quadriparesis (4/5). He also had markedly increased intracranial pressure. CT scan revealed a large high attenuating lesion in right CP angle with gross hydrocephalus. The patient was operated with the clinical and radiological diagnosis of right sided acoustic tumor with brainstem compression. Radical tumour excision was performed, seven days following VP shunt. Patient had immediate postoperative deterioration followed by a steady recovery. The possibility of a secretory choroid plexus papilloma is discussed.