# Askin Tumor in an Adult: Recognizing a Rare Chest Wall Presentation of Ewing Sarcoma

## TL;DR

A rare case of Ewing sarcoma in an adult presented as a chest wall mass initially mistaken for a benign tumor, highlighting the need for careful diagnosis.

## Contribution

This case report presents an unusual adult presentation of Ewing sarcoma with a focus on diagnostic challenges and clinical management.

## Key findings

- The tumor was initially misdiagnosed as a benign lesion due to its appearance on imaging.
- The diagnosis was confirmed through histopathology and molecular testing after the lesion progressed.
- The case emphasizes the importance of considering rare malignancies in atypical presentations.

## Abstract

Ewing’s sarcoma (ES) is an uncommon and aggressive bone tumor most commonly seen in children and adolescents. Chest wall involvement in adults is particularly rare. We report a 39-year-old woman with chest wall ES. She presented to the emergency department with unrelated symptoms, including flank pain and fever. A chest wall mass was incidentally identified on abdominal CT. Initial imaging had shown a well-circumscribed lesion that resembled a benign entity such as a lipoma or inclusion cyst, but over time, it progressively enlarged. Diagnosis was confirmed by imaging, histopathology, and molecular testing. Management included broad surgical excision and chemotherapy. Chest wall ES in adults is an atypical occurrence that may initially resemble benign diseases. This case highlights the importance of maintaining a broad differential diagnosis, especially for incidental or indolent-appearing soft tissue lesions, and demonstrates the diagnostic value of correlating evolving imaging findings with clinical judgment over time.