Angiocentric glioma from a perspective of A-B-C classification of epilepsy associated tumors.

Angiocentric glioma (AG) is a newly-classified, very rare, WHO grade I central nervous system (CNS) lesion, occurring usually in children and young adults. Only 52 patients with AG have been reported so far, making it one of the rarest neuropathological entities. Hereby we present two new cases of AG in young subjects with detailed neuropathological investigations and a neuroradiological picture along with a brief summary of all already published literature reports of this tumor. Histopathological examination of the resected tissue from both cases revealed similar changes characteristic of AG. The tumors were composed of spindle-like, elongated cells, forming characteristic pseudorosettes around vessels and diffusively infiltrating surrounding tissue, trapping neurons between tumor cells. Noticeably, some neoplastic cells encrusting vessels extended far beyond the main tumor mass. Hypothetically, this may be responsible for the recurrence of the tumor even in the case of apparently total excision. In immunohistochemistry, AG cells were glial fibrillary acidic protein (GFAP) and vimentin positive, also exhibiting a strikingly significant epithelial membrane antigen (EMA) dot-like staining pattern. In one of the cases, electron microscopy revealed ependymal differentiation features such as microvilli and cilia. Taken together, all these data strongly confirm a dual astroglial-ependymal nature of the tumor. Follow up corroborates benign character of this neoplasm. Both AGs reported here were immunonegative for the product of the mutated IDH-1 gene what, according to our best knowledge, has never been reported so far. It may suggest that in their pathogenesis AGs differ from grade II astrocytomas, which in most cases harbor a mutation of IDH-1. Noteworthy, neuroimaging in our cases was relatively characteristic but not conclusive, therefore biopsy (at least) is mandatory. A newly proposed so called "A-B-C" classification of long-term epilepsy-associated tumors (LEATs) places AG in a category named ANET. The authors shortly review the A-B-C classification of LEATs.

Dysembryoplastic neuroepithelial tumour (DNT). Is the mechanism of seizures related to glutamate? An immunohistochemical study.

Dysembryoplastic neuroepithelial tumour (DNT) is a rare low-grade, mixed neuronal and glial tumour, usually associated with pharmacologically intractable, complex partial or generalised seizures which date from childhood. The prognosis after surgery is favourable. We present a classic case of DNT occurring in an 18-year-old male, who presented simple partial seizures without signs of raised intracranial pressure. CT and MR demonstrated focal mass located in the right temporal lobe. Histologically there were found the features of a typical DNT architecture with mixed cellular composition. The response to surgery was excellent. The tumour has not recurred, and the control of seizures remained good. Immunostaining for glutamate receptor GluR-2 showed stronger immunopositivity in neurones dispersed within the tumour and especially in margins of lesion as compared with apparently normal cerebral cortex. The expression of both excitatoryamino acid transporterproteins EAAT1 and EAAT2 was weaker then in normal cortex and uneven. This perhaps may explain the mechanism of seizures (elevated glutaminergic stimulation), and may suggest the excitotoxic damage of neurones.

[Current diagnostic methods in normotensive hydrocephalus]. / Wspólczesne metody diagnostyki wodoglowia normotensyjnego.

Based on literature of the last 30 years we present the current view concerning diagnosis of the communicating hydrocephalus. Till now various methods of the assessment of hydrocephalus have been used in order to select patients for shunt treatment. No single factor, considered apart from the other diagnostic criteria, is sufficient to undertake the decision of shunting. According to current opinion the lumbar infusion test is the most valuable in the assessment of hydrocephalus, supporting us with the data of pressure-volume relations in patient. Based on our own experience the infusion test is not only useful in the preoperative investigation, but also for the assessment of proper shunt function.

[The usefulness of lumbar infusion test in the evaluation of the intracranial volume pressure compensation in hydrocephalus before and after shunt insertion]. / Przydatnosc doledzwiowego testu infuzyjnego w ocenie wewnatrzczaszkowej kompensacji objetosciowo-cisnieniowej u chorych z wodoglowiem przed i po zalozeniu zastawki.

The analysis is presented of selected parameters of the lumbar infusion tests performed in hydrocephalic patients before and after shunt. In properly functioning shunt (50 cases) the mean values of the variables are on an average twice lower than before shunt. In patients with shunt malfunction (surgically verified in 7 out of 10 suspected cases) the values of the parameters are similar before and after shunt and are statistically significant. Lumbar infusion test is proved very useful in the detection of shunt malfunction, particularly when it is possible to compare it to the test performed before shunt.