Differential Diagnosis for Leptomeningeal Enhancement
- Single Most Likely Diagnosis
- Meningioma: This is a common cause of leptomeningeal enhancement, particularly in adults, due to its high prevalence and tendency to show dural-based enhancement on MRI.
- Other Likely Diagnoses
- Metastatic disease: Leptomeningeal carcinomatosis from cancers such as breast, lung, or melanoma can cause enhancement due to tumor spread along the leptomeninges.
- Inflammatory or infectious meningitis: Conditions like viral, bacterial, or fungal meningitis can lead to leptomeningeal enhancement due to inflammation.
- Sarcoidosis: Neurosarcoidosis can cause leptomeningeal enhancement due to granulomatous inflammation.
- Do Not Miss Diagnoses
- Subarachnoid hemorrhage: Although it might not always present with enhancement, missing a subarachnoid hemorrhage can be catastrophic, and it should be considered, especially in the appropriate clinical context.
- CNS lymphoma: Primary CNS lymphoma can present with leptomeningeal enhancement and is critical to diagnose early due to its aggressive nature and need for prompt treatment.
- Leptomeningeal metastases from primary CNS tumors: Tumors like medulloblastoma or glioblastoma can spread through the CSF pathways, causing leptomeningeal enhancement.
- Rare Diagnoses
- Neurosyphilis: A rare cause of leptomeningeal enhancement, particularly in the context of tertiary syphilis.
- Histiocytosis: Conditions like Langerhans cell histiocytosis can rarely cause leptomeningeal enhancement.
- Erdheim-Chester disease: A rare form of non-Langerhans cell histiocytosis that can involve the CNS and cause leptomeningeal enhancement.
- IgG4-related disease: A systemic fibroinflammatory disease that can rarely involve the meninges and cause enhancement.