Facts
* Leptomeningeal carcinomatosis refers to the spread of cancer cells to the leptomeninges, the thin membranes that cover the brain and spinal cord. This can occur when cancer cells from a primary tumor in another part of the body spread to the cerebrospinal fluid (CSF) and invade the leptomeninges. Leptomeningeal carcinomatosis is a serious and often terminal condition that can cause symptoms such as headache, seizures, and neurological deficits.
* Most common tumors metastasize to meninges are breast, lung, melanoma
* No identifiable primary malignancy in 2-4% of cases
* Headache is the most common presenting symptom.
* Diagnosis relies on cytological examination (CSF cytology or leptomeningeal biopsy). CSF markers and radiographic findings also can strongly support diagnosis.
* Short median survival even with aggressive treatment
Imaging modalities such as ultrasound, computed tomography (CT), magnetic resonance imaging (MRI), and X-ray can be used to visualize and diagnose leptomeningeal carcinomatosis. Here is a summary of the findings that may be observed on each modality:
Ultrasound:
- Ultrasound uses high-frequency sound waves to produce images of the body.
- Leptomeningeal carcinomatosis may not be visible on ultrasound due to the limited resolution of the technique.
- However, ultrasound may be able to detect abnormalities in the structure of the brain or spinal cord that may be suggestive of leptomeningeal carcinomatosis, such as changes in the thickness or texture of the meninges.
Computed Tomography (CT):
- Leptomeningeal carcinomatosis may appear as a diffuse enhancement of the leptomeninges on CT images.
- CT may also be able to identify other findings associated with leptomeningeal carcinomatosis, such as hydrocephalus (excess fluid in the brain) or brain edema (swelling).
- However, it is important to note that CT has limited sensitivity for detecting leptomeningeal carcinomatosis and may not be able to detect early or mild cases.
Magnetic Resonance Imaging (MRI):
- Leptomeningeal carcinomatosis may appear as a diffuse enhancement of the leptomeninges on MRI images.
- MRI may also be able to identify other findings associated with leptomeningeal carcinomatosis, such as hydrocephalus or brain edema.
- MRI may also demonstrate meningeal enhancement, thick, clumped nerve roots, enhancing nodular deposits on surface of roots or CNS structures, coexisting parenchymal, epidural or bony metastases
- MRI is generally more sensitive than CT for detecting leptomeningeal carcinomatosis, and may be more accurate in identifying early or mild cases.
It is important to note that the choice of imaging modality will depend on the specific clinical presentation and the availability of the equipment. MRI is generally considered the imaging modality of choice for evaluating leptomeningeal carcinomatosis, but CT or ultrasound may also be used in certain cases. In addition to imaging, the diagnosis of leptomeningeal carcinomatosis may also be confirmed by performing a lumbar puncture to examine the CSF for the presence of cancer cells.
References:
- Balm M, et al. Leptomeningeal carcinomatosis: presenting features and prognostic factors. Arch Neurol 1996 (July 1996).
- These images were contributed to this radiology teaching file courtesy of our radRounds Partner, RadiologyinThai.com.
