# Leptomeningeal disease

Source: https://onco.cc/terms/leptomeningeal-disease/  
OnCo record `leptomeningeal-disease` (Term). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Cancer cells spreading in the fluid and membranes that bathe the brain and spinal cord, rather than as a solid lump. It causes headaches, nerve palsies and confusion and has been one of the hardest situations to treat.

## Summary

Occurs in 5-10% of solid tumours (breast, lung, melanoma) and in leukaemia and lymphoma; diagnosed by MRI and cerebrospinal fluid cytology or ctDNA. Median survival has been weeks to months. Treatments are intrathecal chemotherapy or trastuzumab, craniospinal radiotherapy (proton craniospinal showed benefit at MSK), and increasingly CNS-penetrant drugs such as osimertinib at high dose, tucatinib and T-DXd. CNS prophylaxis in high-risk leukaemia and lymphoma exists to prevent it.

## Fields

- Kind: Term
- Last checked: 2026-09-09
- Also known as: leptomeningeal; leptomeningeal metastases; leptomeningeal carcinomatosis; carcinomatous meningitis

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Leptomeningeal_cancer
- Wikipedia: https://en.wikipedia.org/wiki/Leptomeningeal_cancer

## Connected records

- terms: [Brain metastases (intracranial disease)](https://onco.cc/terms/brain-metastases/), [CNS penetration (brain-penetrant drugs)](https://onco.cc/terms/cns-penetration/), [Intrathecal therapy (lumbar puncture, Ommaya reservoir)](https://onco.cc/terms/intrathecal-therapy/), [Palliation in advanced triple-negative breast cancer: brain, bone, pleura, skin and end of life](https://onco.cc/terms/tnbc-symptom-control-palliation/), [Whole-brain radiotherapy (WBRT)](https://onco.cc/terms/wbrt/)
- fronts: [Chemotherapy](https://onco.cc/fronts/chemotherapy/), [Radiation Therapy](https://onco.cc/fronts/radiation/)
- cancers: [Brain metastases (secondary brain tumours)](https://onco.cc/cancers/secondary-brain-tumours/), [EGFR-mutated non-small-cell lung cancer](https://onco.cc/cancers/egfr-mutant-nsclc/), [HER2-positive breast cancer with brain metastases](https://onco.cc/cancers/her2-positive-breast-brain-metastases/), [Metastatic cancer (cancer that has spread)](https://onco.cc/cancers/metastatic-cancer/)

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