Metastatic Undiff erentiated Pleomorphic Sarcoma of Kidney: Presenting as Hematuria - A Case Report

Pleomorphic undifferentiated sarcoma (PUS) is an extremely aggressive soft-tissue sarcoma that occurs most commonly in the trunk and the extremities but is extremely rare in the kidney. This entity has no distinctive clinical or radiological signs for diagnosis. It has high local recurrence and distant metastasis rates along with poor prognosis. We describe a case of PUS of the left kidney with urinary bladder metastases. Radiological investigations suggested an initial diagnosis of multifocal urothelial carcinoma; however, a definitive and confirmatory diagnosis of PUS was made on the basis of histopathological and immunohistochemical examination. Subsequently, left nephroureterectomy along with bladder cuff excision was performed and postoperative histopathology revealed PUS. Follow-up investigations revealed metastatic deposits of tumor in the base of the urinary bladder for which an endoscopic surgery of transurethral resection of the bladder tumor was performed. The histopathological findings were consistent with metastatic high-grade PUS of the kidney with metastasis to the bladder.