RESUMO
Meningiomas are common central nervous system tumors with a wide range of morphological variants, assigned World Health Organization (WHO) Grades I - III. We report an extremely rare rhabdoid, papillary and clear cell meningioma (WHO Grade III) in a 29-year-old female, who presented with diplopia and headache over a few days, 2 years ago. Magnetic resonance imaging showed a well-circumscribed, lobulated, predominantly solid and contrast-enhancing lesion in the right temporal, parietal and occipital lobes. On routine staining, the tumor did not display classical meningioma features. A wide immunohistochemical panel ruled out metastasis and endorsed the meningothelial nature of the lesion (positivity for epithelial membrane antigen and vimentin). Electron microscopy did not show usual hallmarks of meningioma but was helpful in excluding other tumors. Even though the three variants are associated with aggressive behavior, the patient is currently asymptomatic. The concurrent use of different techniques was essential for diagnosis.
Assuntos
Meningioma , Tumor Rabdoide , Humanos , Imageamento por Ressonância Magnética , Neoplasias Meníngeas , Vimentina/metabolismoRESUMO
Motoneuron death induced by sciatic nerve transection in neonatal rats has been related to induction of the neuronal isoform of nitric oxide synthase (nNOS), a diaphorase of which one of the cofactors is nicotinamide adenine dinucleotide phosphate (NADPH). We transected the sciatic nerve of neonatal rats (P2) and examined nNOS expression by immunostaining in neurons of the sciatic pool and of other spinal levels on the 5th day after surgery. No correspondence was observed between the surviving motoneurons and nNOS positive cells. The appearance and distribution of nNOS positive neurons at all spinal levels and laminae were similar to those of adult animals. These results are at variance with previous studies which showed correlation between motoneuron loss after axotomy and number of NADPH-diaphorase positive motoneurons after sciatic transection.
Assuntos
Animais Recém-Nascidos/metabolismo , Neurônios Motores/enzimologia , Óxido Nítrico Sintase/metabolismo , Degeneração Retrógrada/enzimologia , Medula Espinal/enzimologia , Animais , Animais Recém-Nascidos/anatomia & histologia , Axotomia , Contagem de Células , Imuno-Histoquímica , Neurônios Motores/patologia , NADPH Desidrogenase/metabolismo , Óxido Nítrico/metabolismo , Estresse Oxidativo/fisiologia , Isoformas de Proteínas/metabolismo , Ratos , Ratos Wistar , Degeneração Retrógrada/patologia , Nervo Isquiático/enzimologia , Nervo Isquiático/fisiopatologia , Nervo Isquiático/cirurgia , Medula Espinal/crescimento & desenvolvimento , Medula Espinal/patologiaRESUMO
In order to ascertain the immediate histopathological changes of rat brain following experimental surgical injury, fragments of left parietal cortex were obtained through craniotomy and fixed by immersion. Next, the animals were killed by perfusion with the same fixative used for the respective biopsy. Five groups of rats were tested, each for one different fixative. Dark neurons were by far the most prominent feature in surgically traumatized tissue, following both immersion and perfusion with all five fluids. They were morphologically identical at both sites, and fixatives with widely different chemical composition, e.g. Bouin's fluid and buffered glutaraldehyde, had no influence on their aspect. It is suggested that shrunken neurons are not to be interpreted systematically as artefacts, but also represent a form of short-latency cellular reaction to injury.
Assuntos
Lesões Encefálicas/patologia , Córtex Cerebral/patologia , Animais , Biópsia , Masculino , RatosRESUMO
A case of central nervous system actinomycosis is reported. A 33-year-old male complained of headache, vomiting and blurred vision lasting for eight days prior to admission. On examination, a right hemiparesis, as well an intracranial hypertension were detected. The cerebrospinal fluid showed mild lymphomononuclear hypercytosis. Necropsy disclosed three abscess in the cerebral hemispheres, in addition to moderate cerebral edema on the left side but without purulent leptomeningitis. Actinomyces filaments and granules were demonstrated in the cerebral and lung abscessess. The Brazilian literature on actinomycosis is reviewed and six published cases with nervous system involvement were found. Relevant clinical and anatomical aspects of the cases and of the present one are discussed.
Assuntos
Actinomicose/patologia , Abscesso Encefálico/patologia , Adulto , Autopsia , Abscesso Encefálico/microbiologia , Diagnóstico Diferencial , História da Medicina , Humanos , Abscesso Pulmonar/microbiologia , Abscesso Pulmonar/patologia , MasculinoRESUMO
A 60-year-old woman developed progressive spastic crural paraplegia and global anesthesia and global anesthesia below T10, succumbing to urinary infection and bronchopneumonia 8 months after the onset of symptoms. At necropsy, the spinal cord was completely destroyed by a necrotic intramedullary cysticercus at T8. Six cysticerci were found in the brain. A review of the 17 published cases of intramedullary cysticercosis (including this one) showed this condition to be clinically indistinguishable from spinal cord tumours. The surgical prognosis was fair in 8 of 11 operated patients. The role of hematogenous and ventriculo-ependymal pathways in the pathogenesis of intramedullary cysticercosis was examined. The topographical distribution of intramedullary cysticerci (5 cervical, 12 thoracic, 2 lumbar, none sacral) was found to be statistically proportional to the blood flow to each of these regions; this favours the hematogenous route of infestation. The low spinal cord blood flow (100 times less than that to the brain), the type of vascularization of the cord (low calibre vessels under low pressure) and peculiarities of the cord tissue (such as its harder consistency) are all thought to be contributory factors accounting for the scarcity of intramedullary cysticerci. No evidence for an ependymal route of spread could be adduced.