Primary renal leiomyosarcoma with a tumor thrombus in the inferior vena cava

INTRODUCTION: We report a rare case of primary renal leiomyosarcoma with a tumor thrombus in the inferior vena cava. CASE PRESENTATION: A 54‐year‐old woman presented with right flank pain and abdominal distension. Physical examination findings were unremarkable. Abdominal computed tomography revealed a heterogeneously enhancing right solid renal mass with a thrombus in the renal vein extending into the inferior vena cava. Magnetic resonance imaging demonstrated a renal tumor with a thrombus about 4 cm below the hepatic vein. Chest computed tomography and bone scintigraphy were negative. The patient underwent right radical nephrectomy and vena cava thrombectomy. Histophathologic evaluation of the resected tumor confirmed the diagnosis of leiomyosarcoma. She underwent no adjuvant therapy. Seven months after surgery, the patient died following a 2‐month history of multiple pulmonary and hepatic metastases. CONCLUSION: This report highlights the importance of considering the possibility of renal leiomyosarcoma invasion to the inferior vena cava, similar to renal cell carcinoma.