Fact-sheet: Lepto meningeal carcinomatosis
Updated on 04/21/2016 at 11:19 PM
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Definition
Meningeal dissemination of a solid tumor or hematologic malignancy.
Several routes of spread:
- Hematogenous route: via arachnoid arterial vessels or choroid plexuses (most frequent mechanism), or retrograde via the venous sinuses.
- Perineural route (head and neck tumors): spread along the cranial nerves with invasion of the meningeal layers up to the subarachnoid spaces.
- Direct route: spread from brain or spinal cord metastases, or by contiguity with bone involvement.
- Iatrogenic route: dissemination during neurosurgical intervention.
Clinical features
Nonspecific:
- headaches
- neurological deficit (cranial nerves +++)
- impaired consciousness
- Seizures
Laboratory findings
Lumbar puncture with CSF analysis:
- Hypercellularity with mixed cell formula
- Elevated protein / Low glucose
- Presence of neoplastic cells +++
CT
Without contrast injection:
- signs of elevated ICP: thickening and tortuosity of the optic nerves, empty sella syndrome, effacement of the sulci...
- hydrocephalus (complication)
After contrast injection (delayed phase):
- leptomeningeal and/or pachymeningeal enhancement, most often nodular.
- Posterior fossa involvement +++
MRI
T2 FLAIR:
- Thickening of the pachymeninges
- Hyperintensity of the cortical sulci
- Hydrocephalus (complication)
T1 after gadolinium injection:
- Leptomeningeal enhancement, often nodular
- Thickening and enhancement of the pachymeninges.
- Thickening and enhancement of the cranial nerves
- Posterior fossa involvement +++
Management
Poor prognosis +++
IV chemotherapy
Intrathecal chemotherapy
Differential diagnosis
Infectious meningitis Granulomatous meningitis ...