Leptomeningeal metastases
Updates to Article Attributes
Leptomeningeal metastases, also know as carcinomatous meningitis, refers to the spread of malignant cells through the CSF space. These cells can be originated both in primary CNS tumours (e.g. drop-metastases), as well as from distant tumours that have metastasised via haematogenous spread.
This article has a focus on subarachnoid space involvement. Please refer on intradural extramedullary metastases for a particular discussion related to the leptomeningeal metastases in the spine. For other intracranial metastatic locations, please refer to the main article on intracranial metastases.
Epidemiology
The demographics follow those of the underlying malignancy.
Clinical presentation
Clinical presentation is varied, but most commonly includes a headache, spine or radicular limb pain or sensory abnormalities, nausea and vomiting, and focal neurological deficits 3. Meningism is only present in a minority of patients (13% 3).
Pathology
The primary intracerebral malignancies that may cause metastases to the subarachnoid space are:
- glioblastoma (GBM) and anaplastic astrocytoma
- medulloblastoma
- sPNET
- ependymoma
- germinoma
- choroid plexus carcinoma
The vast majority of leptomeningeal metastases originates from a widespread metastatic disease (haematogenous spread). The most common primary sites are:
- breast cancer: most common
- lung cancer: most common
- melanoma
- lymphoma
- leukaemia
- gastric carcinoma 4,5
- pancreatic carcinoma 6
- ovarian cancer 7
- colorectal cancer 8
- renal cell cancer 9
- carcinoma of the uterine cervix 10
Radiographic features
MRI
- T1: usually normal
- T1 C+ (Gd): leptomeningeal enhancement is the primary mode of diagnosis, often scattered over the brain in a 'sugar coated' manner
- T2: usually normal
-
FLAIR
- abnormally elevated signal within sulci 2
- can be performed both non-contrast and post-contrast, but is slightly less specific if performed post-contrast 1
Treatment and prognosis
Untreated leptomeningeal metastases have a poor prognosis with patients usually succumbing within a few months, whereas, with treatment, that time may be extended up to 6-10 months 2,3. Treatment can consist of 3:
- intrathecal chemotherapy
- radiotherapy
Differential diagnosis
- leptomeningeal inflammation: leptomeningitis
- slow flow in vessels
- propofol, high oxygen tension, subarachnoid blood can all elevate sulcal FLAIR signal
-<a title="Renal cell cancer" href="/articles/renal-cell-carcinoma-1">renal cell cancer</a><sup> 9</sup>- +<a href="/articles/renal-cell-carcinoma-1">renal cell cancer</a><sup> 9</sup>
- +</li>
- +<li> <a title="carcinoma of the uterine cervix" href="/articles/carcinoma-of-the-uterine-cervix">carcinoma of the uterine cervix </a><sup>10</sup>
References changed:
- 10. Han L, Bhan R, Johnson S, Zak I, Husain M, Al-Abbadi M. Leptomeningeal Metastasis in a Patient with Squamous Cell Carcinoma of the Uterine Cervix: Report of a Case and Review of the Literature. Diagn Cytopathol. 2007;35(10):660-2. <a href="https://doi.org/10.1002/dc.20705">doi:10.1002/dc.20705</a> - <a href="https://www.ncbi.nlm.nih.gov/pubmed/17854087">Pubmed</a>