# Intracardiac Ewing-Like Sarcoma: A Diagnostic and Therapeutic Challenge

**Authors:** Victor Oyervides-Ortiz, Leonel Gomez-Llanos, Antonio Garza-Cruz, Ivett Miranda-Maldonado, Victor Oyervides-Juarez

PMC · DOI: 10.7759/cureus.101698 · 2026-01-16

## TL;DR

This paper presents a rare case of a deadly heart tumor resembling Ewing sarcoma, highlighting the difficulties in diagnosis and treatment.

## Contribution

The paper reports a rare intracardiac Ewing-like sarcoma case and emphasizes its diagnostic and therapeutic challenges.

## Key findings

- Intracardiac Ewing-like sarcomas are exceptionally rare and difficult to diagnose.
- The tumor led to severe complications and death despite surgical and chemotherapy interventions.
- Multidisciplinary care is crucial for managing such aggressive cardiac tumors.

## Abstract

Ewing-like sarcomas are rare malignancies that typically arise in bone or soft tissue, with intracardiac presentations being exceptionally uncommon and associated with diagnostic uncertainty and high mortality due to anatomical constraints and therapeutic challenges. We report the case of a 22-year-old male who presented with progressive dyspnea and was found to have a large biatrial mass originating from the interatrial septum, resulting in atrial obstruction, pericardial effusion, and reduced systolic function. Subtotal surgical resection revealed a malignant small round cell tumor with an immunohistochemical profile positive for CD99 and NKX2.2, consistent with an Ewing-like sarcoma, although molecular confirmation was not available. Postoperative treatment with systemic chemotherapy was complicated by severe neutropenia, ventilator-associated pneumonia, and superimposed cardiogenic compromise, culminating in death on hospital day 35. Intracardiac Ewing-like sarcomas represent a diagnostically challenging and highly aggressive entity with a grave prognosis due to limited surgical resectability, hemodynamic compromise, and heightened susceptibility to treatment-related complications. This case highlights the narrow therapeutic window in patients with cardiac involvement and underscores the importance of multidisciplinary evaluation and careful administration of intensive therapy.

## Linked entities

- **Proteins:** CD99 (CD99 molecule (Xg blood group)), NKX2-2 (NK2 homeobox 2)
- **Diseases:** neutropenia (MONDO:0001475)

## Full-text entities

- **Genes:** CD99 (CD99 molecule (Xg blood group)) [NCBI Gene 4267] {aka HBA71, MIC2, MIC2X, MIC2Y, MSK5X}, NKX2-2 (NK2 homeobox 2) [NCBI Gene 4821] {aka NKX2.2, NKX2B}
- **Diseases:** cardiogenic compromise (MESH:D013575), death (MESH:D003643), neutropenia (MESH:D009503), dyspnea (MESH:D004417), malignancies (MESH:D009369), Ewing-Like Sarcoma (MESH:D012512), pneumonia (MESH:D011014), cardiac involvement (MESH:D006331), atrial obstruction (MESH:D000402), pericardial effusion (MESH:D010490)
- **Species:** Homo sapiens (human, species) [taxon 9606]

## Figures

2 figures with captions in the complete paper: https://tomesphere.com/paper/PMC12906906/full.md

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Source: https://tomesphere.com/paper/PMC12906906