# Case report: Navigating treatment pathways for cardiac intimal sarcoma with PDGFRβ N666K mutation

## TL;DR

A rare cardiac tumor case highlights how genomic profiling can guide treatment choices and adapt to genetic changes over time.

## Contribution

This case report demonstrates the clinical utility of genomic profiling in guiding and adapting treatment for cardiac intimal sarcoma.

## Key findings

- Genomic testing identified a PDGFRβ N666K mutation and MDM2/CDK4 amplifications, leading to effective pazopanib treatment.
- Recurrence showed loss of the PDGFRβ mutation and reduced expression, indicating the need for adaptive treatment strategies.
- PDGFRβ signaling is highlighted as a potential strategic target in cardiac intimal sarcoma.

## Abstract

In the realm of rare cardiac tumors, intimal sarcoma presents a formidable challenge, often requiring innovative treatment approaches. This case report presents a unique instance of primary intimal sarcoma in the left atrium, underscoring the critical role of genomic profiling in guiding treatment. Initial genomic testing unveiled a somatic, active mutation in PDGFRβ (PDGFRβ N666K), accompanied by MDM2 and CDK4 amplifications. This discovery directed the treatment course toward pazopanib, a PDGFRβ inhibitor, following irradiation. The patient’s response was remarkable, with the therapeutic efficacy of pazopanib lasting for 16.3 months. However, the patient experienced a recurrence in the left atrium, where subsequent genomic analysis revealed the absence of the PDGFRβ N666K mutation and a significant reduction in PDGFRβ expression. This case report illustrates the complexities and evolving nature of cardiac intimal sarcoma treatment, emphasizing the potential of PDGFRβ signaling as a strategic target and highlighting the importance of adapting treatment pathways in response to genetic shifts.