Leptomeningeal disease (also known as LMD, leptomeningeal metastases, or LM) is cancer in your cerebrospinal fluid and in your leptomeninges, the membranes that surround your brain and spinal cord. It happens when an advanced cancer spreads from part of your body to your cerebrospinal fluid and leptomeninges.

When cancer spreads to the cerebrospinal fluid surround the brain and spinal cord and/or the lining of the brain and spinal cord, it causes an aggressive disease called leptomeningeal disease, or LMD. Learn about MD Anderson’s program focused on better understanding and treating this disease.

When cancer cells are found in your leptomeninges or CSF, this is called leptomeningeal metastases (LM). LM stick onto nerves as they exit your brain and spinal cord, causing weakness and numbness. LM can also clog your leptomeninges and prevent CSF from being drained properly, causing CSF and pressure to build up inside of your brain.

The current tools available for detecting the spread of cancer into the cerebrospinal fluid (CSF) are cytology, neurologic examination, and neuroimaging. All three of these methods can be applied in concert to reach a diagnosis, but they all suffer from a lack of sensitivity, leading to delays in treatment in many cases.

Leptomeningeal disease occurs when cancer cells migrate from your breast, lung, or some other part of your body to your cerebrospinal fluid (CSF). This liquid circulates nutrients and chemicals to the brain and spinal cord.