Uncommon Glioneuronal Tumors: A Radiologic and Pathologic Synopsis.

Glioneuronal tumors are characterized exclusively by neurocytic elements (neuronal tumors) or a combination of neuronal and glial features (mixed neuronal-glial tumors). Most of these tumors occur in young patients and are related to epilepsy. While ganglioglioma, dysembryoplastic neuroepithelial tumor, and desmoplastic infantile tumor are common glioneuronal tumors, anaplastic ganglioglioma, papillary glioneuronal tumor, rosette-forming glioneuronal tumor, gangliocytoma, and central neurocytoma are less frequent. Advances in immunohistochemical and molecular diagnostics have improved the characterization of these tumors and favored the description of variants and new subtypes, some not yet classified by the World Health Organization. Not infrequently, the histologic findings of biopsies of glioneuronal tumors simulate low-grade glial neoplasms; however, some imaging findings favor the correct diagnosis, making neuroimaging essential for proper management. Therefore, the aim of this review was to present key imaging, histopathology, immunohistochemistry, and molecular findings of glioneuronal tumors and their variants.

Frameless image-guided neuroendoscopy training in real simulators.

BACKGROUND: Over the last decade, neuroendoscopy has re-emerged as an interesting option in the management of intraventricular lesions in both children and adults. Nonetheless, as it has become more difficult to use cadaveric specimens in training, the development of alternative methods was vital. The aim of this study was to analyze the performance of a real simulator, in association with image-guided navigation, as a teaching tool for the training of intraventricular endoscopic procedures. METHODS: 3 real simulators were built using a special type of resin. 1 was designed to represent the abnormally enlarged ventricles, making it possible for a third ventriculostomy to be performed. The remaining 2 were designed to simulate a person's skull and brain bearing intraventricular lesions, which were placed as follows: in the foramen of Monro region, in the frontal and occipital horns of the lateral ventricles and within the third ventricle. In all models, MRI images were obtained for navigation guidance. Within the ventricles, the relevant anatomic structures and the lesions were identified through the endoscope and compared with the position given by the navigation device. The next step consisted of manipulating the lesions, using standard endoscopic techniques. RESULTS: We observed that the models were MRI compatible, easy and safe to handle. They nicely reproduced the intraventricular anatomy and brain consistence, as well as simulated intraventricular lesions. The image-based navigation was efficient in guiding the surgeon through the endoscopic procedure, allowing the selection of the best approach as well as defining the relevant surgical landmarks for each ventricular compartment. Nonetheless, as expected, navigation inaccuracies occurred. After the training sessions the surgeons felt they had gained valued experience by dealing with intraventricular lesions employing endoscopic techniques. CONCLUSION: The use of real simulators in association with image-guided navigation proved to be an effective tool in training for neuroendoscopy.

Surgical removal of small petroclival meningiomas.

UNLABELLED: Treatment of large petroclival meningiomas causing brain stem compression is surgical removal followed by radiotherapy or radiosurgery if the lesion was partially resected. The management of small petroclival meningiomas is, however, controversial. Clinical observation, radiosurgery and surgical removal are the options of treatment. The natural history of these tumours is not well known. Published series of patients treated with radiosurgery are not comparable with surgical series because the latter also includes large size tumours. In this paper we present a series of 18 patients with small petroclival meningiomas (diameter

A model for foramen ovale puncture training: Technical note.

BACKGROUND: Trigeminal neuralgia is a common cause of facial pain, characterized by shock-like pain affecting one or more branches of the trigeminal nerve. When conservative treatment fails and microdecompression is not indicated, percutaneous procedures are helpful. This percutaneous approach is done by a puncture up to the Gasserian ganglion, through the foramen ovale. Although simple and safe, this puncture demands some expertise from neurosurgeons. For that, a partnership between neurosurgeons and bio-engineers has developed a model for foramen ovale puncture, allowing practice for residents and young neurosurgeons. METHOD: A model for foramen ovale puncture has been created by interposition of synthetic materials over a skull, simulating the human face. FINDINGS: This model has shown great similarity with that found in conventional surgeries, even upon repeated testing by experienced functional neurosurgeons and young residents. CONCLUSION: This model for foramen ovale puncture training has demonstrated valuable help for initial practicing of this common neurosurgical procedure, particularly in centers where there are not many cadavers available for training.

Primary central nervous system lymphomas in immunocompetent patients.

OBJECTIVES: Primary central nervous system lymphoma (PCNSL) is a rare pathology and is most often seen in immunodeficient patients. This article presents our casuistic of PCNSL in immunocompetent patients and make a literature review on this issue with focus on recent advances, investigations, and controversies in diagnosis and management of this pathology. MATERIAL AND METHODS: Nine patients operated in the last years in our clinics are analysed in relation to sex, age, time of symptoms, procedures and adjuvant treatment. Posteriorly the results are compared with those in the preview literature. RESULTS: The age ranged from 44-68 years (middle of 66 years); 62.5% of the patients were female. The mean time of symptoms, when the diagnostic was made, was 3.2 months (range 1-6 months). The most common symptoms were hemiparesis (present in 75% of the patients) headache (37.5%) seizures (25%) and ataxia (25%). The most common localization was the parietal, frontal and temporal lobe surface with 25% of the patients for each localization. Five patients (50%) were treated with stereotactic biopsy, three with surgery (37.5%) and one (12.5%) with both of them. Five patients (62.5%) were submitted to pos-operative radiotherapy as adjuvant treatment. In relation to the histology, the most common cell type was Diffuse B Cells. CONCLUSIONS: This study demonstrated that complete surgical resection followed by radiotherapy have shown good results. In opposition to the literature, the authors regard chemotherapy as a secondary line treatment and recommend its use only in some selected cases.

Primary central nervous system lymphomas in immunocompetent patients

Objetivos. En este trabajo presentamos nuestra casuística de linfomas cerebrales primarios en pacientes immunocompetentes comparandolo con los datos previos de la literatura, con especial enfoque en los recientes avances, investigaciones, y controversias acerca del diagnóstico y manejo terapéutico de estas patologías. Material y método. Nueve pacientes operados el año pasado en nuestra clínica con diagnóstico de PCNLS son analizados en relación al sexo, edad, tiempo de sintomatología, procedimientos y tratamiento. Posteriormente, los resultados son comparados con los de la literatura. Resultados. La edad varió entre 44-68 años (media de 60,6 años); 62,5% de los pacientes fueron del sexo femenino; el tiempo medio de duración de los síntomas antes del diagnóstico de la enfermedad varió de 1-6meses, con un rango medio de 3,2 meses. Los síntomas clínicos más frecuentes fueron : hemiparesia (75%),cefalea (37,5), crisis convulsivas (25%) y ataxia (25%).Las localizaciones predominaron en las superficies delos lóbulos parietal, temporal y frontal con un 25% para cada una de las localizaciones citadas. Cinco pacientes (50%) fueron tratados con biopsia estereotáxica, tres con cirugía (37.5%) y uno (12.5%) con ambas. Cinco pacientes (62,5%) fueron sometidos a radioterapia postoperatoria como tratamiento adyuvante. En relación con el tipo histológico predominó el linfoma de células difusas tipo B. Conclusiones. Este estudio demostró que la resección quirúrgica, combinada con biopsia por esterotaxia y la radioterapia dan buenos resultados. Los autores recomiendan la quimioterapia solamente como segunda línea de tratamiento, en pacientes seleccionados

Objetctives. Primary central nervous system lymphoma(PCNSL) is a rare patology and is most often seen in immune-deficient patients. This article presents our casuistic of PCNSL in immunocompetent patients and make a literature review on this issue with focus on recent advances, investigations, and controversies in diagnosis and management of this patology. Matherial and methods. Nine patients operated in the last years in our clinics are analysed in relation to sex, age, time of symptoms, procedures and adjuvant treatment. Posteriorly the results are compared with those in the preview literature. Results. The age ranged from 44-68 years (middle of 66 years); 62,5% of the patients were female. The mean time of symptoms, when the diagnostic was made, was 3.2 months (range 1-6 months). The most common symptoms were hemiparesis (present in 75%of the patients) headache (37.5%) seizures (25%) and ataxia (25%). The most common localization was the parietal, frontal and temporal lobe surface with 25%of the patients for each localization. Five patients(50%) were treated with stereotactic biopsy, three with surgery (37.5%) and one (12.5%) with both of them. Five patients (62,5%) were submitted to pos-operative radiotherapy as adjuvant treatment. In relation to the hystology, the most common cell type was Difuse B Cells. Conclusions. This study demonstrated that complete surgical ressection followed by radiotherapy have shown good results. In opposition to the literature, the authors regards chemotherapy as a secondary line treatment and recommends its use only in some selected cases

Fibrous dysplasia in combination with aneurysmal bone cyst presenting as a subarachnoid haemorrhage.

Fibrous dysplasia (FD) is a rare tumour, representing 2.5% of all bone tumours and 7% of benign tumours. Aneurysmal bone cyst (ABC) is also an uncommon pathology, usually associated with a secondary vascular lesion consisting of an arteriovenous malformation. In this article, we relate a case report of a young female with a rare combination of FD with aneurysmal bone cyst presenting as a subarachnoid haemorrhage (SAH). Despite the possibility of clinical treatment of these lesions, this report demonstrates that symptomatic lesions may be successfully managed by surgical resection. The authors' opinion is that this treatment should be individualised depending on particularities of each case, such as localisation of the lesion, biopsy results and image exams features. We also present a critical literature review of diagnostic methods and therapeutical options for both ABC and FD, with emphasis on controversial topics surrounding these issues.

Orbital apex syndrome due to aspergillosis: case report.

We report the case of a 73-year-old female who presented facial numbness and pain in the first division of the trigeminal nerve, ptosis, diplopia and visual loss on the right side for the previous four months. The neurological, radiological and histological examination demonstrated a rare case of invasive fungal aspergillosis of the central nervous system, causing orbital apex syndrome, later transformed in temporal brain abscess. She died ten months later due to respiratory and renal failure in spite of specific antimycotic therapy.

April 2001: a 70 year old woman with recurrent meningioma.

The April Case of the Month (COM). The contributors report a case of a 70 year-old woman with recurrent meningiomas, one of which showed rhabdoid and lipomatous differentiation. Histopathological study of the first and second previous resections showed only typical meningothelial meningioma. On the third craniotomy, a new tumor specimen showed an admixture of classic meningothelial meningioma with lipomatous and rhabdoid foci. Immunohistochemical studies showed diffuse reactivity for epithelial membrane antigen and vimentin, as well as focal positivity for desmin and smooth muscle actin in the areas with rhabdoid features and S100 protein in the lipomatous foci. The presence of these three different and concomitant histological patterns only in the third surgical resection might support a metaplastic origin and, also, corroborates the concept that rhabdoid features are suggestive of an aggressive behavior.

Minimally invasive approach to traumatic intracerebral hematomas.

Trauma is one of the leading causes of death in Brazil. We report on 28 cases of traumatic intracerebral hematomas operated on via a minimally invasive approach. A simplified method of localization and right placement of the burr hole is described in details, as well as the technique used in all cases. Every patient was submitted to pre- and postoperative CT scan (computerized tomography) and had the volume of the hematoma measured before the surgical procedure to compare the efficacy of the treatment. No patient needed a second operation, even though in some cases there were residual hematomas. We believe that this approach can be done with safety and replace a standard craniotomy in selected cases.

Pilocytic astrocytoma following radiotherapy for craniopharyngioma: case report.

Administration of fractionated doses of irradiation is part of the adjutant therapy for CNS tumours such as craniopharyngiomas and pituitary adenomas. It can maximise cure rates or expand symptom-free period. Among the adverse effects of radiotherapy, the induction of a new tumour within the irradiated field has been frequently described. The precise clinical features that correlate irradiation and oncogenesis are not completely defined, but some authors have suggested that tumors are radiation induced when they are histologically different from the treated ones, arise in greater frequency in irradiated patients than among normal population and tend to occur in younger people with an unusual aggressiveness. In this article, we report a case of a papillary astrocytoma arising in a rather unusual latency period following radiotherapy for craniopharyngioma.

[Choroid plexus carcinoma: report of 15 cases]. / Carcinoma de plexo coróide: relato de quinze casos.

Choroid plexus carcinoma (CPC) are rare central nervous system tumours derived from choroid plexus epithelium, affecting mainly children under 3 years of age. We present a clinical, epidemiological and histopathological study of 15 cases of CPC. Ten patients were male. Age ranged from 4 months to 21 years (mean=3,4). The lateral ventricles were affected in 73,3% of cases. Main symptom were: hydrocephalus (62.5%), intracranial hypertension (25%) and convulsion (12.5%). The patients were treated by surgery with partial resection in 75% of cases and total resection in 25%. There was one death due to surgical complication, 85.7% of patients had recurrence of tumours with mean survival rate of 13.6% months after diagnosis. Only one patient remain alive 5 years after initial treatment. These results support the poor prognosis and high mortality rate of CPC.

Thrombosis of the internal carotid artery secondary to soft palate injury in children and childhood. Report of two cases.

Trauma to the soft palate is a uncommon event during childhood. Stroke following intraoral trauma is also rare, but has been well documented by the current literature as a potentially serious complication. In this article, we report 2 cases of posttraumatic internal carotid artery thrombosis depicted by imaging studies. We discuss pathogenesis, and the literature is reviewed.

[Stereotactic-guided surgery for cavernous angiomas]. / Cirurgia estereotáxica guiada para angiomas cavernosos.

Intracerebral cavernous angiomas may cause hemorrhage, epileptic seizures and neurological deficits. The diagnosis of these lesions became easier with the advent of the magnetic resonance image (MRI). Radical resection is the treatment of choice. Due to frequent subcortical or deep location, image-guided techniques, such as stereotactic-guided surgery, offer many advantages as smaller skin incision and craniotomy, less brain manipulation with consequently lower morbidity. We present a series of nine cavernous angiomas treated by stereotactic-guided radical surgical resection. The diagnosis was done by MRI and confirmed by pathologic studies in all cases. Mean age of patients was 30 years old (range 20-54 years). Postoperative morbidity occurred in two cases: one patient had a convulsion on the third postoperative day and the other presented dysphasia and hemiparesis on the second postoperative day, both with total recovery. Total resection of the lesion was possible in all cases with no neurological deficit.

Saphenous vein graft bypass in the treatment of giant cavernous sinus aneurysms: report of two cases.

Two cases of giant intracavernous aneurysms treated by high flow bypass with saphenous vein graft between the external carotid artery (ECA) and branches of the middle cerebral artery (MCA) are presented. Very often these aneurysms are unclippable because they are fusiform or have a large neck. Occlusion of the internal carotid artery (ICA) is the treatment of choice in many cases. This procedure has however a high risk of brain infarction. Revascularization of the brain by extra-intracranial anastomosis between the superficial temporal artery (STA) and branches of the MCA is frequently performed. This procedure provides however a low flow bypass and brain infarction may occur. We report two cases of giant cavernous sinus aneurysms treated by high flow bypass and endovascular balloon occlusion of the ICA. Immediate high flow revascularization of MCA branches was achieved and the patients showed no ischemic events. Follow-up of 8 and 14 months after operation shows patency of the venous graft and no neurological deficits. Angiographic control examination showed complete aneurysm occlusion in both cases.

Perforating and leptomeningeal branches of the anterior communicating artery: an anatomical review.

The morphological variability, diameter, and length of the anterior communicating artery (ACoA) are important factors in clinical and surgical decisions. This artery presents branches that supply the optic nerves and chiasm, the lamina terminalis, the hypothalamus, and the subcallosal region. The ACoA has the most frequent incidence of saccular aneurysms in the anterior portion of the circle of Willis. Lesions to the ACoA's branches may be related to neuropsychological sequelae such as amnesia, confabulation and personality changes, besides other basal ganglia syndromes. In this paper, anatomical studies of the ACoA and its branches are reviewed and the results of an anatomical study carried out in our laboratory presented.

[Arteriovenous malformations of the central nervous system. Analysis of 53 cases]. / Malformações arteriovenosas do sistema nervoso central. Análise de 53 casos.

Fifty-three patients with arteriovenous malformation (AVM) were studied. The mean age at the time of diagnosis was 32.5 +/- 11.5 years (range 3 to 56 years); the sex ratio was male 1.9:1 female. The most common clinical presentation was intracranial hemorrhage, followed by focal neurological signs, headache, epilepsy, and acute deep coma. Fourty-three (82%) out of the total number of AVM were supratentorial and had the following distribution: 10 temporal lobe, 9 pariental lobe, 6 frontal lobe, 3 occipital lobe, 3 frontotemporal, 4 corpus callosum/pericalosal, 1 temporo-occipital, 1 temporoparieto-occipital, 6 deep-located (3 thalamic, 3 basal ganglia). Spetzler-Martin grade II was seen in 17 cases (32%), grade III in 21 cases (39%), and grade IV in 10 cases (19%). AVM-associated aneurysms were detected in 3 patients (5.6%). All three cases were middle artery aneurysms ipsilateral to AVM. Twelve (32%) out of 37 operated patients were submitted to embolization prior to surgery. AVM was totally removed in all cases except one. Embolization without posterior surgery was used in 11 patients; in 3 of them, embolization was partial. Two patients were neither embolized nor operated on. Three patients were, submitted to radiosurgery because they were poor candidates to embolization and/or surgery. Mortality rate was 1.8%. All patients returned to their normal life function after a period of recovery. Associated or isolated therapies should be individualized to each patient with AVM and is likely to provide results better than the expected outcome without any treatment.

[Oligodendroglioma: a pathological and clinical study of 15 cases]. / Oligodendrogliomas. Estudo anatomopatológico e clínico de 15 casos.

Oligodendrogliomas account for 4-5% of primary central nervous system tumours with a slow and infiltrative growth. We report the clinical and pathological findings of 15 cases of oligodendrogliomas. Eight patients were males and 7 were females. The ages ranged between 17 and 66 years, with a mean of 39.73 years. The symptoms reflected the growth and topography of the tumours; migraine (60%) and seizures (60%) were the most frequent symptoms. Frontal (n = 6), parietal (n = 2), temporal (n = 1) and occipital (n = 1) lobes were affected. Five patients undergone total resection of the tumor and 10 were submitted to partial resection, from which 3 received adjuvant radiotherapy, 1 adjuvant chemotherapy and 1 chemotherapy and radiotherapy. The overall recurrence rate was 60% for a 32 month follow up. Five recurrences were observed in patients submitted only to the surgical treatment and 4 in which adjuvant radio or chemotherapy were performed. These results are similar with the literature and may contribute to further understanding the biological behavior of these rare tumours.

[Craniopharyngioma: clinical, epidemiological and pathological findings in 25 cases]. / Craniofaringiomas. Achados clínicos, epidemiológicos e anatomopatológicos de 25 casos.

We report the clinical and pathological findings of 25 cases of craniopharyngiomas. Fourteen patients were males and 11 were females. The ages ranged between 3 and 64 years, with a mean of 30.52 years. The symptoms reflected the growth and topography of the tumours; visual disorders (72%), headache (68%), vomits (40%) and papilledema (24%) were the most frequent symptoms. Twelve cases were suprasellar; 10 tumours arose from sellar region, from which 8 presented suprasellar extension; frontal lobe (n = 2) and ponto cererebellar angle (n = 1) were also affected. Eleven patients undergone total resection of the tumor and 14 were submitted to partial resection, from which 1 received adjuvant chemotherapy. The overall recurrence rate was 48%. Eight recurrences were observed in the patients submitted to partial resection and 4 in which total resection were performed. These results are similar with the literature, corroborating to the extension of residual tumour after the surgical resection as the main prognostic factor for this neoplasm.

[Ependymomas: Clinical, epidemiological and clinico-pathological findings of 22 cases]. / Ependimomas. Achados clínicos, epidemiológicos e anatomopatológicos de 22 casos.

Ependymomas are composed of neoplastic ependymal cells, affecting mainly children and young adults. We report the clinical and pathological findings of 22 cases of ependymomas. Fourteen patients were males and 8 were females. The ages ranged between 1 and 58 years, with a mean of 24.63 years. The symptoms reflected the growth and topography of the tumours; muscle weakness (59.1%), gait disorders (36.3%), sensitive disorders (36.3%), hyperreflexia and intracranial hypertension syndrome were the most frequent symptoms. Ten tumours affected the medulla, 7 the cerebral hemispheres, 2 the cerebral ventricles and 1 brain stem. Seven patients were submitted total resection of the tumor, from which one received adjuvant radiotherapy. 15 other patients were submitted to partial resection; from which 4 received adjuvant radiotherapy, 3 adjuvant chemotherapy and 1 chemotherapy and radiotherapy. The recurrence rate was 18.2%. These results are similar with the literature and may contribute to further understanding the biological behavior of these tumours.