Renal Pelvis and Renal Calices Sarcomatoid Carcinoma: A Case Report

Introduction: Sarcomatoid carcinoma is one of the malignant neoplasms characterized by the ability to differentiate into both epithelial tissue and mesenchymal tissue. And it is rare in urinary system with a high degree of malignancy and prognosis is poor. Patient Concerns: The present article reports a 63-year-old man presented with recurrent left flank pain for two years. Radiological tests suggested a space-occupying lesion in left kidney with enlarged paranephric /retroperitoneal lymph nodes. Diagnosis: The pathological diagnosis following left nephrectomy indicated renal pelvis and renal calices sarcomatoid carcinoma; pTNM: T4N0M0. Interventions: No radiotherapy or chemotherapy were performed after the surgery and underwent rapid growth. Outcomes: The patients died six months later. Conclusion: Renal pelvis and renal calices sarcomatoid carcinomas is a highly malignant tumor and difficult to diagnose at its early stage. Definite diagnosis relies on the combination of immunohistochemistry (IHC) and morphological analyses and there currently is no effective treatment.