Leptomeningeal Enhancement

Sagittal T1W MR image post gadolinium shows extensive leptomeningeal enhancement (arrrows) along the cerebral sulci and cerebellar folia.

Differential Diagnosis:

• Leptomeningeal carcinomatosis: usually due to breast or lung metastasis, or primary CNS tumor. In children, the most common cause is medulloblastoma.
• Meningitis (bacterial, tuberculosis, coccidiodomycosis)
• Neurosarcoidosis: often involves the basal cistern

Facts: Leptomeningeal Carcinomatosis

• Hematogenous spread of malignancy (i.e., breast, lung) or direct extension by CNS tumor
• MRI with contrast administration best imaging tool to detect this abnormality, much more sensitive than CT
• Imaging Findings: smooth or nodular enhancement along the leptomeninges (extending into sulci), hyperintensity of sulci on FLAIR, hydrocephalus (which may be the only sign seen on CT)

Our case: Leptomeningeal carcinomatosis from esophageal cancer

References:

1. O'Brien WT. Top 3 differentials in radiology: a case review, 2009.

2. Lev MH, Heisserman J, Shetty S. Q&A color review of neuroimaging, 2008.