Publications by authors named "Manoel A Paiva Neto"

Article Synopsis
  • The Kaplan-Meier method can overestimate the risk of cancer coming back, especially when other events like death happen first, but the Aalen-Johansen method can give a more accurate picture by considering these events.
  • A study looked at research articles about meningiomas (a type of brain tumor) since 2020 and found that only a few used the better method.
  • It showed that not using the Aalen-Johansen method mostly led to overestimating the recurrence risk, especially in older patients with more serious tumors.
View Article and Find Full Text PDF

Background: Cancer patients in general and glioblastoma patients, in particular, have an increased risk of developing complications from the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and reaching a balance between the risk of exposure to infection and the clinical benefit of their treatment is ideal. The aggressive behavior of this group of tumors justifies the need for a multidisciplinary team to assist in clinical decisions during the current pandemic. Brazil is now ranked #2 in the number of cases and deaths from COVID-19 pandemic, and existing disparities in the treatment of neuro-oncology patients in Brazil will challenge the clinical and surgical decisions of this population, possibly affecting global survival.

View Article and Find Full Text PDF

Objective: Pilocytic astrocytoma (PA) is rare in adults comprising 5.1% of the primary central nervous system tumors. The aim is to describe the first Brazilian series of adult patients with PA and compare its features with the available literature.

View Article and Find Full Text PDF

EPNs comprise a heterogeneous group of neuroepithelial tumors, accounting for about 10% of all intracranial tumors in children and up to 30% of brain tumors in those younger than 3 years. Actually, the pattern therapy for low-grade EPNs includes complete surgical resection followed by radiation therapy. Total surgical excision is often not possible due to tumor location.

View Article and Find Full Text PDF

Amniotic fluid has been investigated as new cell source for stem cells in the development of future cell-based transplantation. This study reports isolation of viable human amniotic fluid-derived stem cells, labeled with multimodal iron oxide nanoparticles, and its effect on focal cerebral ischemia-reperfusion injury in Wistar rats. Middle cerebral artery occlusion of 60 min followed by reperfusion for 1 h, 6 h, and 24 h was employed in the present study to produce ischemia and reperfusion-induced cerebral injury in rats.

View Article and Find Full Text PDF

Objective: The study reviewed the histology of cases of grade I meningiomas with spontaneous necrosis, grade I without necrosis and grade II meningiomas, to evaluate the histological and immunohistochemical factors of the patients' prognosis, while correlating the clinicopathological features with the clinical follow-up of the patients.

Methods: A review of 47 cases from the Department of Pathology of UNIFESP was performed and the samples were submitted to immunohistochemical examination with the p53 protein, Ki-67 cell proliferation factor and progesterone receptor markers.

Results: A greater expression was found in the progression of several degrees of aggressiveness for p53 and Ki-67, and a higher frequency of progesterone receptors in the lower degrees.

View Article and Find Full Text PDF

Background: Previous studies have demonstrated remarkable tropism of mesenchymal stem cells (MSCs) toward malignant gliomas, making these cells a potential vehicle for delivery of therapeutic agents to disseminated glioblastoma (GBM) cells. However, the potential contribution of MSCs to tumor progression is a matter of concern. It has been suggested that CD133 GBM stem cells secrete a variety of chemokines, including monocytes chemoattractant protein-1 (MCP-1/CCL2) and stromal cell-derived factor-1(SDF-1/CXCL12), which could act in this tropism.

View Article and Find Full Text PDF

Background: Ependymoma (EPN), the third most common pediatric brain tumor, is a central nervous system (CNS) malignancy originating from the walls of the ventricular system. Surgical resection followed by radiation therapy has been the primary treatment for most pediatric intracranial EPNs. Despite numerous studies into the prognostic value of histological classification, the extent of surgical resection and adjuvant radiotherapy, there have been relatively few studies into the molecular and cellular biology of EPNs.

View Article and Find Full Text PDF

The purpose of this study was to evaluate spontaneous necrosis as a possible isolated factor for progression and recurrence in grade I meningiomas classified according to the current World Health Organization (WHO) classification. Meningiomas are the most frequently reported primary intracranial tumours, accounting for more than 35%. The 2016 WHO classification of central nervous system tumors stratifies meningiomas in grades I (benign), II (atypical), and III (malignant), according to histopathological aspects and the risk of progression or recurrence.

View Article and Find Full Text PDF

Background: Neurofibromas are benign nerve sheath tumors that usually affect peripheral nerves and are related to neurofibromatosis type 1; however, they have not been described as a cause of intraparenchymal brain tumor.

Case Description: We report a case of intracranial myxoid neurofibroma in a 19-year-old female patient manifested as an intense and progressive cephalea, followed by nausea, vomiting, photophobia, and phonophobia. Computed tomography and magnetic resonance imaging showed an extant, expansive left frontoparietal parafalcine/parasagittal tumor.

View Article and Find Full Text PDF

Background Although germ cell tumors and pineal cell tumors account for most of the histologic tumor subtypes, > 17 different tumors can arise in this location. We report a rare case of a low-grade oligodendroglioma that arose in the pineal region. Clinical Presentation A young woman complaining of a headache underwent magnetic resonance imaging that showed a mass in the pineal region and mild hydrocephalus.

View Article and Find Full Text PDF
Article Synopsis
  • Fusiform aneurysms in the cerebellar arteries are uncommon and require specific surgical techniques based on whether the aim is to maintain or block blood flow in the parent artery.
  • The reported case involves a 32-year-old man with a fusiform aneurysm in the superior cerebellar artery who underwent successful aneurysm trapping and bypass surgery, resulting in a smooth recovery.
  • The authors emphasize that in certain cases of ruptured fusiform aneurysms, particularly for patients in good condition with limited collateral blood supply, a bypass combined with aneurysm trapping should be considered, and a review of current treatment options is also included.
View Article and Find Full Text PDF

In this paper, the authors present the case of a patient with multifocal intradural extramedullary ependymoma, and they review 18 previously reported cases. A 32-year-old man presented to the authors' institution with a 1-month history of partial medullary syndrome. Magnetic resonance imaging of the neuraxis revealed multifocal intradural extramedullary lesions at the bulbomedullary junction and C2-3, T5-11, L-2, L-4, L-5, and sacrum.

View Article and Find Full Text PDF

The improvement of surgical techniques as well as the introduction of new surgical instruments promoted the use of keyhole craniotomies in neurosurgery. We evaluated the technical aspects of the supra-orbital keyhole approach considering the indications, limitations, and complications of this approach to treat anterior cranial fossa and parasellar meningiomas. Twenty-four patients (21 females; mean age, 53 + or - 8.

View Article and Find Full Text PDF

Objective: Giant pituitary adenomas (> or =40 mm) pose a major management challenge. We describe the experience of a single surgeon and a dedicated neuro-endocrine team with multimodality treatment of these tumours in three specialized institutions.

Design: Retrospective data set analyses.

View Article and Find Full Text PDF

Objective: Endonasal and supraorbital "eyebrow" craniotomies are increasingly being used to remove craniopharyngiomas and tuberculum sellae meningiomas. Herein, we assess the relative advantages, disadvantages, and selection criteria of these 2 keyhole approaches.

Methods: All consecutive patients who had endonasal or supraorbital removal of a craniopharyngioma or tuberculum sellae meningioma were analyzed.

View Article and Find Full Text PDF

THE DIRECT ENDONASAL transsphenoidal approach to the sella with the operating microscope was initially described more than 20 years ago. Herein, we describe the technique, its evolution, and lessons learned over a 10-year period for treating pituitary adenomas and other parasellar pathology. From July 1998 to January 2008, 812 patients underwent a total of 881 operations for a pituitary adenoma (n = 605), Rathke's cleft cyst (n = 59), craniopharyngioma (n = 26), parasellar meningioma (n = 23), chordoma (n = 18), or other pathological condition (n = 81).

View Article and Find Full Text PDF

Cerebral aneurysms are rare in the pediatric age group and differ from adults' aneurysms in size, localization and incidence. We report a 3-year-old boy with giant middle cerebral artery aneurysms who presented with subarachnoid hemorrhage. The patient was submitted to surgical treatment and the postoperative period was uneventful.

View Article and Find Full Text PDF

Unlabelled: Fibromatosis is a locally aggressive, proliferative fibroblastic lesion affecting musculoaponeurotic structures, most often in the limbs and trunk. Intracranial fibromatosis is extremely rare and requires aggressive treatment to prevent recurrence.

Case Description: We present the case of a 20 year old woman with aggressive skull base fibromatosis.

View Article and Find Full Text PDF

We report our experience with 11 cases of foramen magnum meningiomas, eight originating inside the posterior fossa and three in the caudal region. The mean age of the patients was 50.8 years and the main complaint was cervical headache for at least 18.

View Article and Find Full Text PDF

Posterior longitudinal ligament ossification of cervical spine is a rare condition among caucasians. A 42 years old japanese patient with progressive walking difficulty was diagnosed with this pathology by CT scan and MRI and treated surgically by an anterior approach with arthrodesis. Pathophysiology, racial prevalence, clinical picture, radiological characteristics and surgical approaches options are revised.

View Article and Find Full Text PDF

Olfactory groove meningiomas compromise approximately 8-18% of intracranial meningiomas and harbor frequently large sizes when diagnosticated. We report 13 consecutive cases operated on Hospital São Paulo and Hospital Professor Edmundo Vasconcelos between 1995 and 2003. These patients were retrospectively studied regarding clinical preservation, surgical results and complications.

View Article and Find Full Text PDF

Objective: The aim of this study is to correlationate demographic, radiologic features and proliferative index defined by immunohistochemical expression of Mib-1 in olfactory groove meningiomas, and to observe possible predictive factors of recurrence of this tumor.

Method: There were analysed demographic, clinical and radiological features of 15 patients with olfactory groove meningioma. Fifteen paraffin-embebed tumors were studied by immunohistochemical methods for the expression of proliferative index by the Mib-1.

View Article and Find Full Text PDF

Acoustic neuromas are the most common tumors in the cerebellopontine angle. The molecular mechanisms involved in generation and growth of these tumors are not completely elucidated. Many radiological, clinic and immunohistochemistry data were correlated to tumor growth.

View Article and Find Full Text PDF

Neurocysticercosis is the most frequently observed parasitosis of the central nervous system worldwide. The fourth ventricle is the most frequent site of intraventricular infestation, a location that carries a higher risk for CSF blockage and intracranial hypertension due to CSF blockage. A great number of patients become shunt dependent which carries a poorer prognosis.

View Article and Find Full Text PDF