Neoplastic meningitis

Background

• Also known as Leptomeningeal Carcinomatosis or leptomeningeal metastasis (LM)
• Uncommon and late complication of solid tumors and hematological cancers, approximately 5-8% and 5-15% respectively
• Most common primary tumors associated with LM are breast, lung, and melanoma
• Commonly misdiagnosed due to symptoms mimicking infectious meningitis and chronic headache

Pathophysiology

• Multiple routes tumor cells can gain access to CSF
• Most commonly thought to be through hematogenous spread via arachnoid vessels or direct extension from brain parenchyma

Clinical Features

• Chronic headache
• Nausea and vomiting
• Fever
• Nuchal rigidity
• Altered mental status
• Seizure
• Spinal cord compression (non-traumatic)
  • Limb weakness
  • Dermatomal sensory loss
  • Radicular pain
  • Bladder and bowel dysfunction
• Cranial nerve abnormalities
  • Diplopia
  • Facial weakness
  • Hearing loss
  • Ataxia

Differential Diagnosis

• Meningitis (bacterial, fungal, viral)
• Encephalitis
• Brain and Spinal metastasis

Evaluation

Workup

• CT brain is not sensitive or specific, may show intracranial mass
• MRI brain and spine with contrast preferred (70% sensitivity, 77-100% specificity)
  • Leptomeningeal enhancement
  • Hydrocephalus
  • Subependymal nodules or deposits
• Lumbar Puncture-mainly to rule out infectious etiology in ED
  • Elevated opening pressure
  • Glucose, protein, cell count and cytology can be abnormal
  • Malignant cells on CSF smear

Diagnosis

• Leptomeningeal enhancement or lesions on MRI
• Malignant cells on CSF smear

Management

• Control seizures
  • Benzodiazepines
  • Antiepileptics
  • Intubation if status epilepticus
• Pain management if headache, radicular pain
• Steroids may be indicated depending on severity of symptoms

Disposition

• Admit