Abstract
INTRODUCTION: Up to 10% of patients with renal cell carcinoma present with tumor thrombus in the inferior vena cava. We report that a case of small renal cell carcinoma with tumor thrombus extending above the diaphragm for which transvenous biopsy was performed for diagnosis. CASE PRESENTATION: A 79-year-old man performed computed tomography to evaluate hepatic dysfunction, which revealed intravenous tumor extending above the diaphragm and a 15-mm-sized exophytic tumor in right kidney. Imaging suggested that the renal tumor was renal cell carcinoma. As this tumor was small and exophytic, confirmation of the intravenous tumor being tumor thrombus associated with renal cell carcinoma was difficult. We simultaneously performed transvenous biopsy on the intravenous tumor and percutaneous biopsy on the renal tumor for obtaining histologic diagnoses. The final diagnosis was small renal cell carcinoma accompanied by tumor thrombus above the diaphragm. CONCLUSION: Transvenous biopsy may be useful for the definitive diagnosis of inferior vena cava-tumor thrombus in cases of small renal cell carcinoma.