Left neck undifferentiated sarcoma with synchronous left kidney renal cell carcinoma

Parapharyngeal space sarcomas are rare malignancies and most in the reported literature are synovial sarcomas. Here we present the case of a 27-year-old female with a painless, left-sided neck mass who underwent computed tomography and magnetic resonance imaging evaluation which demonstrated a benign appearing mass that upon resection unexpectedly proved to be a high-grade undifferentiated sarcoma with rhabdoid features. Staging computed tomography revealed a synchronous renal cell carcinoma with clear cell and papillary features. Despite an extensive genetic work-up no underlying cause linking these two cancers was discovered.