Intracranial myopericytoma: a tumour in a rare location.

A 49-year-old female with history of headache, nausea and vomiting with some weeks of evolution, without neurological symptoms. Radiology revealed an expansive lesion near the inferior vermix and cerebellar tonsils, with heterogeneous gadolinium uptake and mass effect on the fourth ventricle, representing a probable extraventricular origin for the lesion. Pathological examination showed a proliferation of oval/spindle cell proliferation with eosinophil cytoplasm and small and monotonous nuclei, without mitoses. The cells had a concentric growth, surrounding thin-walled blood vessels with foci of stromal myxoid degeneration and whorled pattern. The vessels had a haemangiopericytoma pattern and were lined by non-atypical endothelial cells. The tumorous cells expressed vimentin, alpha-smooth actin and heavy-chain caldesmon and were negative for epithelial membrane antigen, protein S100, HMB45, CD34, calponin and desmin, thus providing the final diagnosis of intracranial myopericytoma.

Brain Herniation into Giant Arachnoid Granulation: An Unusual Case.

Arachnoid granulations are structures filled with cerebrospinal fluid (CSF) that extend into the venous sinuses through openings in the dura mater and allow the drainage of CSF from subarachnoid space into venous system. Usually they are asymptomatic but can be symptomatic when large enough to cause sinus occlusion. We report a rare case of a brain herniation into a giant arachnoid granulation in an asymptomatic elderly male patient, which was discovered incidentally.

[Cerebral venous thrombosis: retrospective analysis of 49 cases]. / Trombose venosa cerebral: análise retrospectiva de 49 casos.

INTRODUCTION: Cerebral Venous Thrombosis (CVT) is a rare and potentially life-threatening disease, accounting for about 0.5% of stroke cases. However, it is believed to be an underdiagnosed condition. Early diagnosis requires a high degree of suspicion and appropriate use of imaging modalities. OBJECTIVES: Imagiological and clinical characterization of CVT cases diagnosed at our hospital from 2004 to 2007. METHODS: This study was a retrospective, cross-sectional analysis from 2004 to 2007, using our institution database. We reviewed hospital discharge data to assess the incidence of CVT. The study population consisted of 49 patients. Retrospective review of the clinical data and imaging studies of these patients was then performed. RESULTS: Of the 49 patients with confirmed CVT, 38 were female. Patient age varied between 16 and 75 years, with an average of 42.6 years. Thrombotic risk factors were found in 43 patients; the most frequent was dyslipidemia (n = 22) followed by oral contraceptive use (n = 18). Initial head Computerized Tomography (CT) was normal in six cases. Diagnosis was made by Magnetic Resonance (MR) in 38 cases, Cerebral CT-Venography in 10 cases and Digital Subtraction Angiography in one case. Average time from onset of symptoms to diagnosis was nine days; this was not significantly different when comparing the group diagnosed by MR with the group diagnosed by CT-Venography. Right transverse sinus was the most frequent location of thrombosis (n = 36). Only in four cases thrombosis did not involve the lateral sinuses. CONCLUSIONS: Lateral sinus thrombosis is a frequent variety of CVT, accounting for 91.8% of our cases. A negative Head CT scan does not exclude the presence of cerebral venous thrombosis; therefore appropriate imaging study should be performed whenever there's a high degree of clinical suspicion. Cerebral CT-Venography seems to be a good alternative to MR for the diagnosis of CVT.