Gliomatosis Cerebri Type 1 Mimicking an Ischemic Stroke and Progressing to a Type 2: a Case Study and Literature Review.

Aims: To report a rare clinical case of gliomatosis cerebri, which presented with non-specific clinical, laboratory, and radiological findings. We provide images and stress the importance of differential diagnosis based on imaging, especially magnetic resonance (MR) spectroscopy. Case Presentation: A 73-year-old woman developed a right hemiplegia suggestive of ischemic stroke. Cerebral magnetic resonance imaging (MRI) highlighted a diffuse tumor-related infiltration involving several lobes without contrast enhancement, corresponding to the specific description and definition of gliomatosis cerebri type 1. With the aid of MR spectroscopy, we correctly diagnosed the disease preoperatively, which was finally confirmed pathologically by stereotactic biopsy. During radiological follow-up, a contrast enhancement occurred on cerebral MRI, suggestive of progression to a gliomatosis cerebri type 2. Given a poor performance status, this elderly patient received palliative treatment. Discussion: Gliomatosis cerebri is a relatively rare but well-known entity, which affects mostly middle aged patients. It often presents with confounding clinical and imaging features, thus additional examinations such as MR spectroscopy are almost always necessary before reaching the correct diagnosis before biopsy. Conclusion: Contrast enhancement on cerebral MRI, which is usually absent, is found in case of transformation from type 1 gliomatosis cerebri to type 2. Some features on MR spectroscopy are helpful for gliomatosis cerebri diagnosis: N-acetylaspartate levels are diminished, levels of myoinositol are significantly elevated, but Cho/Cr ratio may be normal.