# Isolated Intraventricular Metastatic Melanoma: A Case Report

## TL;DR

A rare case of melanoma spreading to the brain's ventricles is described, with a novel approach to diagnosis and treatment leading to significant improvement.

## Contribution

A novel method for tissue sampling in isolated intraventricular melanoma is presented, enabling targeted therapies when traditional methods fail.

## Key findings

- A multidisciplinary treatment plan led to considerable regression of ventricular melanoma.
- Molecular testing of a directly obtained biopsy sample enabled targeted therapies.
- Lumbar CSF aspirations failed to yield diagnostic results, necessitating an alternative approach.

## Abstract

Isolated intraventricular melanoma is an infrequent disease presentation that poses unique diagnostic and management challenges. Of the few cases reported in the literature, each has a unique management plan. We present the case of a 64-year-old female with a history of gallbladder melanoma in remission after multiple cycles of chemotherapy and immunotherapy. After eight years, the patient was presented to the emergency department due to cognitive changes, memory issues, headaches, and vomiting. Imaging showed diffuse, bulky, nodular enhancement of bilateral ependyma of the lateral ventricles of unclear etiology. Systemic imaging revealed no additional sites of metastatic disease. Cytologic evaluation through multiple cerebrospinal fluid (CSF) aspirations via lumbar punctures produced unremarkable results. An external ventricular catheter was subsequently placed directly into the right lateral ventricle with no CSF able to be aspirated. Through modulated suction and aspiration, a biopsy sample was obtained through this catheter. Molecular testing of the specimen facilitated the initiation of targeted, combination chemo- and immunotherapies in conjunction with whole-brain radiation therapy. This multidisciplinary, personalized treatment plan ultimately resulted in considerable regression of her ventricular disease burden. This very rare disease presentation, along with our novel approach for tissue sampling, highlights the importance of obtaining specimens for molecular testing to guide targeted therapies that optimize patient outcomes, particularly in instances in which lumbar CSF fails to result in diagnostic yield.