Background
Retroperitoneal undifferentiated sarcomas are rare, highly aggressive mesenchymal tumors with limited available treatment options. Surgical resection ± chemoradiation remains standard of care. However, in unique cases, challenging tumor biology, advanced tumor stage, and the morbidity required of an R0 resection can prohibit management and ultimate cure. Targeted therapies have an increasing role in this setting due to advances in molecular analytics.
Case presentation
Herein, we describe the management of an 11-year-old female with a chemotherapy-refractory large retroperitoneal sarcoma encasing the infrarenal aorta with a large acquired aortic pseudoaneurysm. This is the first report describing the complex approach to a retroperitoneal -fusion ( +) undifferentiated sarcoma confounded by an acquired aortic pseudoaneurysm in a pediatric patient. Preoperative considerations, intra-operative technique, postoperative management, adjuvant therapies and a brief review of the literature are discussed.
Conclusion
Overall, a holistic understanding of the tumor biology and a cohesive multidisciplinary approach is integral to the care and long-term management of these cases.