Diagnostic uncertainty around seizures in advanced malignancy.

A 70-year-old lady with a resected Dukes B colon cancer, receiving adjuvant capecitabine and bevacizumab chemotherapy was admitted with Hickman line sepsis. During her admission, she developed seizures and periods of unresponsiveness and was suspected to have brain metastases. She was started on high dose steroids and sodium valproate and appeared to respond to this treatment. However an MRI scan revealed that she did not have brain metastases but a rare neurological condition called reversible posterior leukoencephalopathy syndrome, which can be fatal if not treated but has a good prognosis if the cause is identified and treated.