Progressive leg pain and weakness.

A 54-year-old man presented with progressive asymmetric leg pain and weakness. He had a history of invasive squamous cell carcinoma that was fully treated 2 years earlier. His leg symptoms progressed relentlessly during several months. Imaging studies demonstrated enhancement of the cauda equina and leptomeninges of the lower spinal cord. Initial cerebrospinal fluid examination showed an elevated protein concentration and lymphocytic pleocytosis with no malignant cells on cytological analysis. There was short-term improvement in symptoms and cerebrospinal fluid abnormalities with intravenous steroids. Two additional cerebrospinal fluid studies showed normal cytological findings, elevated IgG synthesis, and elevated antibody titers to varicella-zoster virus. Over time, the patient worsened, developed cranial neuropathies, and ultimately died. The pathological diagnosis and the approach to the clinical data are discussed.