A 71-year-old female presented with 8 kg weight loss over several months, appetite loss, and leg edema for several weeks. An enhanced computed tomography (CT) scan revealed a 94-mm right renal mass with a bulky tumor thrombus within the IVC to the junction of the IVC and the right atrium, maximum thrombus diameter of 37 mm, a few lung nodules, and para-aortic adenopathy. A transthoracic echocardiogram revealed no tumor within the right atrium. A bone scan revealed no metastasis. A core needle biopsy of the renal mass showed mostly necrotic tissue with a region of clear-cell RCC (ccRCC). Immunohistochemical analysis revealed that PD-L1 was not expressed on tumor cells. The patient was not appropriate for radical surgery because her Karnofsky performance status (KPS) was 40. Systemic immunotherapy was administered for metastatic RCC based on International Metastatic RCC Database Consortium (IMDC) poor-risk classification including KPS < 80%, diagnosis to treatment interval < 1 year, anemia, and hyper calcemia. After 2 cycles of nivolumab and ipilimumab therapy, CT revealed that the primary tumor was stable at 94 mm in diameter and lung nodules were undetectable except for the one in the right lower lobe, but the tumor thrombus was extended within the right atrium. Nivolumab and ipilimumab therapy was changed to pazopanib monotherapy due to disease progression. She had marked improvement in Karnofsky performance status to 70 and resolution of leg edema and appetite loss. Follow-up CT at 4 months after treatment revealed that the renal mass had decreased to 84 mm in diameter, and all lung nodules were undetectable. The tumor thrombus in the right atrium was also undetectable, but the tip of the thrombus remained at level 3. The diameter of the IVC at the renal vein ostium was 15.6 mm. Complete occlusion of the IVC was not observed. She underwent right nephrectomy and IVC thrombectomy after 2 cycles of nivolumab and ipilimumab therapy and pazopanib therapy for 5 months. The surgical method is described below. A cardiac surgeon secured the right upper arm vein and the right femoral vein to prepare for extracorporeal circulation. A middle incision to the xiphoid was made in addition to chevron incision. The right kidney and IVC were exposed. The area around the kidney and the IVC had strong adhesions. The right renal artery was ligated at the aortocaval. A tumor thrombus was confirmed between the common iliac vein bifurcation and the diaphragm by echoic imaging, but no tumor thrombus was observed in the right atrium. A liver surgeon secured the hepatic triad. Furthermore, an incision was made in the epicardium and the IVC was secured above the diaphragm. Since no change in blood pressure was observed when the IVC was clamped above the diaphragm, a decision was made to perform nephrectomy without using extracorporeal circulation. The hepatic triad was clamped using a Pringle, and the IVC (above the diaphragm and on the common iliac vein bifurcation) was clamped. The vascular wall was incised at the bifurcation of the renal vein and the IVC to secure the tumor thrombus. The tumor thrombus was manually removed from the IVC wall. However, dense adhesions were revealed between the tumor thrombus and the wall of the IVC. The IVC was resectable from beneath the hepatic vein to the IVC bifurcation. Unfortunately, the tip of the thrombus could not be removed. Since the tip of the thrombus was macroscopically firm necrotic tissue, no additional excision was performed. The operative time was 9 h, and the bleeding volume was 3000 mL. No surgical complications occurred. CT and a transthoracic echocardiogram 1 week after surgery revealed no metastatic findings and only the mass within the IVC near the right atrium. Treatment for RCC after surgery was not performed because we diagnosed the mass as having no viable cells by pathological findings. 1 year after surgery, the mass has not changed and no metastatic lesions have been observed. Finally, the pathologic diagnosis was ccRCC (7.5 cm, International Society of Urologic Pathologists [ISUP] Grade 3). Macroscopic findings showed a light yellowish-brown color in the margin area and extensive necrosis in the internal red and yellow areas. Histologically, tumor cells with clear cytoplasm and round nuclei were observed at the margin of the lesion. The proportion of residual tumor in the primary tumor was 10–20%. The tumor thrombus tissue was necrotic and replaced by a hemosiderin-phagocytic macrophage population. No viable cells were observed. No tumor was found in the wall of IVC. Immunohistochemical analysis revealed that PD-L1 was expressed on lymphocytes and macrophages infiltrating the tumor, but not on the tumor cells themselves.