Abstract
Leiomyosarcomas (LMS) arising from vascular channel are rare and more often arise from inferior vena cava and pulmonary arteries. Primary renal vein LMS are even rarer and occur predominantly in females with peak in fifth and sixth decade. Preoperative diagnosis is difficult because these are rare tumours and present with symptoms and radiological findings similar to Renal Cell Carcinoma (RCC). We report a case of 55-year-old female who presented with abdominal discomfort with radiology showing a renal mass with features of RCC, radical nephrectomy was done and resected tumour showed an attachment to the wall of renal vein with morphology resembling LMS.