Histological and MR correlations in Gliomatosis cerebri.

The diagnosis of Gliomatosis cerebri (GC) is known to be difficult and is still a matter of debate. In order to better define this entity, we studied clinical, neuroradiological, pathological and follow-up data of 9 patients affected with GC. MRI were done with T1 before and after gadolinium injection, and with T2-weighted images and Flair in 3 cases. Histological confirmation of glial proliferation was obtained in all patients by craniotomy or stereotactic biopsies. Patients were treated and followed-up in our center. The histological analyses highlighted a heterogeneous glial proliferation with various degrees of anaplasia in all the cases including 2 cases of oligodendroglioma, 1 case of anaplastic oligodendroglioma, 2 cases of anaplastic mixed oligoastrocytoma, 1 case of anaplastic astrocytoma, 2 cases of glioblastoma and 1 case of astrocytic proliferation typical of GC. The topography of the tumoral infiltration was characteristic involving mainly the white matter, basal ganglia and thalamus, brainstem and less often hypothalamus. More than two cerebral lobes were involved. Contrast enhancement, mass effect and necrosis were minimal compared to the extent of tumoral infiltration. Patients were treated with various schemes of treatment all including nitrosourea. Survival from diagnosis was under one year except for 2 patients (17 and 14 months). This study shows that the diagnosis of GC needs to be based not on pathological data alone, but on pathological, clinical and, above all, on radiological criteria. Response to therapy could not clearly be observed in GC, despite oligodendroglial component in 6/9 cases. Prognosis of GC was constantly poor.