Primary bilateral leiomyosarcoma of kidneys with metastases at unusual sites- a rare case report

Abstract

Primary Leiomyosarcoma of kidney is rare entity, constituting 0.5-1 % of all invasive renal tumors and bilateral Leiomyosarcoma makes it extremely rare. One such case diagnosed by Ultrasound Sonography Guided Fine Needle Aspiration Cytology is reported here. Needle core biopsy was performed for Immunohistochemical markers . Renal Leiomyosarcomas are difficult to differentiate from Sarcomatoid Renal cell carcinoma, as both tumors have atypical spindle cells. Also it is difficult to differentiate radiologically and clinically.Immunohistochemical markers were done. Smooth Muscle Actin and Vimentin were positive in this tumor, confirming the mesenchymal nature of the tumor.Desmin showed focal positivity. HMB 45, Cytokeratin, EMA were Negative. Since this being a bilateral primary renal leiomyosarcoma with metastases, supposedly the first case with this presentation to be reported, it turned out to be a diagnostic challenge to differentiate from sarcomatoid renal cell carcinoma. Prognosis of renal sarcoma is poor.