DISSEMINAZIONE LIQUORALE DEI GLIOMI A BASSO GRADO DI MALIGNITA: ASPETTI TC ED RM IN TRE CASI PEDIATRICI

Leptomeningeal and ventricular spread through the cerebrospinal fluid (CSF) of primary Central Nervous System tumors has been described in primitive neuroectodermal tumors, ependymomas and anaplastic gliomas. In low-grade gliomas, CSF seeding is extremely rare and the possibility of its occurence is usually ignored. We observed 6 cases of histologically verified low-grade gliomas (3 adults and 3 children). We report the MR findings of the 3 pediatric cases. Pathological diagnosis was low grade astrocitoma in 2 cases and oligodendroglioma in the third. All cases were studied by pre and post-contrast Computed Tomography and Magnetic Resonance imaging. In one case, the spinal cord was also examined. CSF seeding presented as several nodules located mainly in the and sylvian cysterns, in the fourth ventricle and in the lateral ventricles. Diffuse meningeal seeding was also observe as linear enhancement associated with nodules located in the intracranial subarachnoid spaces. The occurrence of CSF seeding in low grade gliomas, although rare, is probably more common than previously thought and is obviously important in planning therapy.