# A rare case of vision loss caused by leptomeningeal metastasis of lung adenocarcinoma: a case report and literature review

## TL;DR

A rare case of lung cancer causing vision loss through brain metastasis was successfully treated with a targeted drug after detecting a specific mutation.

## Contribution

This case highlights the survival benefit of trametinib in treating leptomeningeal metastasis with BRAF non-V600E mutations.

## Key findings

- A patient with LM from lung cancer experienced vision loss and responded to trametinib treatment.
- BRAF non-V600E mutation detection in CSF guided effective targeted therapy.
- Literature review suggests improved survival with CSF chemotherapy and MEK inhibitors in similar cases.

## Abstract

Leptomeningeal metastasis (LM) is a fatal complication with increasing incidence in patients with non-small cell lung cancer. Herein, we present the case of a patient who presented with complete vision loss due to LM and achieved a survival benefit from treatment with trametinib. The treatment was prescribed based on the detection of a BRAF non-V600E mutation in the cerebrospinal fluid (CSF). We reviewed the literature and evaluated survival benefits in patients with LM harboring BRAF non-V600E mutations treated with CSF chemotherapy and mitogen-activated extracellular signal-regulated kinase inhibitors.