Meningeal carcinomatosis in head and neck cancer. Report of six cases and review of the literature.

Head and neck cancer has rarely been reported to be a cause of meningeal carcinomatosis. These tumors are known more for their local invasiveness rather than distant metastasis. This would appear to preclude meningeal involvement, but close proximity to multiple cranial nerves may provide an access to the meninges. Six cases of head and neck cancer with meningeal invasion are presented. All six cases had malignant cells in their cerebrospinal fluid. Three cases had malignant cells recovered from a ventricular specimen after lumbar punctures were negative. The most common clinical finding on presentation was cranial nerve involvement. The optic nerve was involved most often with nerves VI and V the next most frequent. Headache was present in four patients and seizures occurred in two. No patient had meningismus. Our current treatment plan involves insertion of an Ommaya Reservoir and intraventricular methotrexate. Only patients whose primary head and neck tumor shows a response to systemic therapy undergo Ommaya placement. Meningeal carcinomatosis in head and neck cancer may be more prevalent than previously thought and the likely mechanism is via direct extension rather than hematogenous spread.