This report details the evolution of a case of herpes simplex encephalitis to chronic granuloma in a 13-year old female who, at the age of 8, suffered herpes simplex virus type 1 encephalitis. Eight months later, she developed an intracranial hypertension syndrome with the onset of a new lesion in the necrosed zone of her right temporal lobe, with no viral presence in the cerebrospinal fluid. The histologic characteristics were those of chronic granuloma with multinucleated giant cells and calcifications. Initially treated for neurosarcoidosis, the patient remained steroid-dependent for 4 years and the steroids could only be withdrawn by treatment with Infliximab. This type of evolutive pattern has probably been completely overlooked until now; it can only be accurately diagnosed by biopsy. It was initially mistaken for neurosarcoidosis.