Leptomeningeal Carcinomatosis

Fig. 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).