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.

Pilocytic astrocytoma (PA) is a grade I glial neoplasm arising mainly in the cerebellum of children. Herein, the authors report a case of PA in a 21 year-old male patient, who presented headache, vomiting and delayed pubertal development. Serum level of cortisol and testosterone corresponded to 32.8 ug/dl and 0.19 ng/ml, respectively. The computed tomography/magnetic resonance (CT/RM) imaging showed an expansive process compromising suprasellar/hypothalamic region and determining hydrocephalus. The patient underwent resection of the process. Histological evaluation revealed a glial neoplasm constituted by loose glial tissue, small microcysts, areas of dense piloid tissue and Rosenthal fibers. The neoplastic cells were immunoreactive for glial fibrillary acidic protein (GFAP) and negative for chromogranin and synaptophysin. The diagnosis of PA was then established..

Objectives: The temporal venous drainage is essential to the favorable prognosis of the patients whose require subtemporal and petrosal approaches to the skull base. To obtain adequate exposure of the middle and posterior fossae the tentorial split is an important step. The aim of this paper is discuss the anatomical aspects of the venous patterns of the temporal lobe stressing the relevant correlations with the petrosal and tentorial approaches. Methods: The authors review the anatomic, surgical and radiological aspects of the temporal venous drainage with special concerning about the preservation of the temporal lobe integrity during the transtentorial and petrosal approaches. Results: The vein of Labbè is the most important vein of the lateral group of veins and it is present in almost 100% of the cases. The inferior system of veins is composed by three different groups of veins in the anterior, medial and posterior portions of the temporal lobe. The anteroinferior veins can be present in 70% of the temporal lobes, the medial-inferior veins in 40% and the posteroinferior in 90% of the cases. The anteroinferior and the posteroinferior groups of veins drain in an independent pattern of the lateral group in more than 10% of the cases. Conclusions: Despite of the preservation of the vein of Labbè during the transtentorial and petrosal approaches, temporal infarction has been observed as a complication of such approaches. The patterns of the venous drainage at the inferior temporal surface should be observed carefully in order to avoid temporal infarction. Angiographic preoperative studies are crucial to evaluate such venous anatomy. The correct positioning of the tentorial incisions according with the temporal venous anatomy and the intermittent gentle temporal retraction are the technical aspects, which permit the better final results.

Primeira submissão em 25/12/11 Última submissão em 17/02/12 Aceito para publicação em 26/02/12 Publicado em 20/06/12 Lymphoplasmacyte-rich meningioma (LPM) is a rare variant of meningioma, which is characterized by massive inflammatory cell infiltration and rare meningothelial elements. The authors report the clinicopathological features of a LPM located at the right parietal convexity in a patient with generalized tonic-clonic seizures and paresthesia in the left arm. The surgical specimen consisted of a gray nodule measuring 3.5 × 3 × 1.8 cm. At microscopy, a few epithelioid cells associated with numerous lymphocytes/ plasma cells were identified. Positive immunoexpression for epithelial membrane antigen (EMA) and progesterone receptor was found in the epithelioid cells, and positive staining for CD3, CD5 and CD20 in the inflammatory cells. Thus, the diagnosis of LPM was established.