Sagital T1 (post contrast) MR image shows nodular/irregular enhancement of the leptomeninges, especially in the posterior fossa (arrows). The patient was found to have esophageal carcinoma.

Facts

* Most common tumors metastasize to meninges are breast, lung, melanoma
* No identifiable primary malignancy in 2-4% of cases
* Headache is the most common presenting symptom.
* Diagnosis relies on cytological examination (CSF cytology or leptomeningeal biopsy). CSF markers and radiographic findings also can strongly support diagnosis.
* Short median survival even with aggressive treatment

Radiographic Findings

* Hydrocephalus
* Meningeal enhancement
* Thick, clumped nerve roots
* Enhancing nodular deposits on surface of roots or CNS structures
* Coexisting parenchymal, epidural or bony metastases

References:
Balm M, et al. Leptomeningeal carcinomatosis: presenting features and prognostic factors. Arch Neurol 1996 (July 1996).

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