[Pseudo-tumoral lesions of multiple sclerosis].

Three patients underwent a cerebral biopsy for clinical and radiological features suggesting a brain tumor. In all cases, the lesion contained large pleomorphic astrocytes that might have led to the erroneous diagnosis of grade II astrocytoma. However, the presence of foamy macrophages, demyelination and the relative preservation of axons led to the definitive diagnosis of multiple sclerosis which was confirmed by the subsequent clinical course.