Fatal herpes encephalitis in a patient with small cell lung cancer following prophylactic cranial radiation--a case report with review of literature.

Herpes simplex virus 1 (HSV-1) is the principal cause of viral necrotizing encephalitis in developed countries. Small cell carcinoma of the lung accounts for about 15% of all lung cancer. HSV induced encephalitis (HSE) following prophylactic cranial irradiation (PCI) in SCLC is rare. Here, we describe the case of a 58-year-old woman with limited stage SCLC, multiple sclerosis (MS) and cutaneous lupus who developed fatal HSE following PCI. We review the literature to investigate the inter-relationships between these diseases and management of HSE.