# Salvage resection after immunotherapy for giant undifferentiated pleomorphic sarcoma of the chest wall

## TL;DR

A patient with a rare chest wall tumor responded well to immunotherapy followed by surgery, remaining cancer-free for two and a half years.

## Contribution

Demonstrates successful use of immunotherapy and salvage surgery for a rare, aggressive chest wall sarcoma.

## Key findings

- Nivolumab and ipilimumab caused significant tumor regression in a patient with undifferentiated pleomorphic sarcoma.
- Salvage surgery after immunotherapy led to complete removal of the tumor and two and a half years of disease-free survival.
- Histopathology confirmed high tumor mutational burden in the sarcoma, suggesting a potential biomarker for treatment response.

## Abstract

We present a rare case of primary undifferentiated pleomorphic sarcoma (UPS) of the chest wall in a 45-year-old male, initially diagnosed as sarcomatoid pleural mesothelioma via computed tomography (CT)-guided biopsy. CT revealed a large tumor measuring 13 × 12 cm occupying the left thoracic cavity, with extensive invasion into the left first through fifth ribs and the adjacent lung parenchyma. The patient was referred to our hospital and treated with a combination of nivolumab and ipilimumab, resulting in marked tumor regression. Upon reevaluation, the diagnosis was revised to sarcoma, and the patient subsequently underwent salvage surgery, including resection of the left upper lung lobe and first through fifth ribs. Histopathology confirmed tumor mutational burden-high UPS. The patient has remained disease-free for two and a half years postoperatively. This case demonstrates the potential efficacy of immune checkpoint inhibitors in multimodal treatment for select cases of chest wall UPS.