Positive CSFHSVPCR in patients with GBM: A note of caution

Because two patients with temporal lobe glioblastomas had herpes simplex (H SV) DNA detected in CSF using PCR at the time of their presentation, we rev iewed our laboratory's experience and performed PCR on a bank of 159 frozen CSF samples from patients with glioblastoma multiforme and other neurologi c disorders. Based on the inability to detect HSV in any other tumor sample , we conclude that the positive HSV PCR in our two index patients most like ly represented false-positive results. A diagnosis of HSE should not be mad e by PCR alone when the clinical presentation is atypical.