Intraoperative detection of inferior vena caval tumor thrombus extending from metastatic lymph node of renal cell carcinoma using ultrasonography.

A 67-year-old man consulted our department with gross hematuria. Computed tomography (CT) revealed a huge renal tumor with a paracaval metastatic lymph node (mLN). Right total nephrectomy was planned for the renal tumor diagnosed as renal cell carcinoma preoperatively. Just before the resection of the renal vein and artery, intraoperative ultrasonography revealed an inferior vena caval tumor thrombus (IVCTT) extending from the mLN. Ultrasonography clearly and dynamically demonstrated a rhythmic flapping movement of the IVCTT with blood flow in the inferior vena cava. Following right radical nephrectomy, IVCTT resection with the vessel wall was performed to reduce the risk of pulmonary tumor thrombus. Histopathological diagnosis of the renal tumor was clear cell renal cell carcinoma, and the resected IVCTT was confirmed histopathologically as tumor involvement from the mLN of the renal cell carcinoma. Intraoperative ultrasonography can detect IVCTT extending from the mLN, whereas CT cannot.