Posterior Reversible Encephalopathy Syndrome Mimicking Cerebral Metastasis: Contraindication for Biopsy

The posterior reversible encephalopathy syndrome (PRES) is a well described entity of white matter pathology. PRES is triggered by numerous different factors such as acute elevated arterial hypertension, immunosupressive therapy, chemotherapy, etc. The case of a 67-year old woman is presented. The patient was treated for breast cancer 10 months ago and because of acute disorientation a magnetic resonance imaging (MRI) was performed. In the MRI biparieto-occipital hyperintense lesions were seen. Brain metastases were suspected. After chemothe - rapy and hypertonia and the typical appearance of the lesions in the MRI, PRES was also suspected. Before initializing the surgery for an open biopsy a follow-up MRI had been performed (2 weeks after initial MRI). In follow-up MRI the lesions disappeared completely proving the diagnosis of PRES. PRES can be misdiagnosed as a tumour and surgery could be mistakenly performed. It’s important to keep the differential diagnosis of PRES in mind when radiologic features of the syndrome are present.