Comparison of cisternal and lumbar CSF examination in leptomeningeal metastasis.

We compared cisternal and lumbar CSF examination in 14 patients suspected of having leptomeningeal metastasis from cancer. Malignant cells were present in 12 patients--in both cisternal and lumbar CSF in nine patients and only in cisternal CSF in three. Cisternal CSF cytologic examination should be considered in patients suspected of having leptomeningeal metastasis if lumbar CSF is nondiagnostic.