Renal cell carcinoma with multiple bone metastases effectively treated by a combination of tyrosine kinase inhibitor, robot-assisted partial nephrectomy, and metastasectomy

Abstract

Key clinical message: Maintaining a disease-free status for a long time in cases of renal cell carcinoma with multiple bone metastases and repeated recurrences is challenging. What matters most in the multidisciplinary approach is the treatment strategy. Although this is a case where multidisciplinary treatment resulted in long-term CR during the TKI era, the treatment strategy is still relevant now that treatment options have increased.

Abstract: Recent advances in medications, such as immune checkpoint inhibitors (ICIs) and tyrosine kinase inhibitors (TKIs), have improved metastatic renal cell carcinoma (mRCC) outcomes. We report a case of mRCC with bone metastasis that was successfully treated using a multidisciplinary approach. Here, we present a case of a 56-year-old man with left renal cancer and large and painful bone metastases at the 11th thoracic vertebrae (Th11). Therefore, a metastasectomy of Th11 was performed. Systemic treatment with TKI, robot-assisted partial nephrectomy, and metastasectomy were then administered. No recurrence was observed in >2 years. Long-term disease-free survival with the TKI-era multidisciplinary approach in a patient with mRCC remains significant when considering treatment sequences, especially now that drug treatment options-including ICIs-have increased. Treatment strategy and indication and timing of resection of the primary lesion and metastasectomy should be carefully considered in each case.

Keywords: metastasectomy; metastatic renal cell carcinoma; multidisciplinary treatment; robot‐assisted partial nephrectomy; tyrosine kinase inhibitor.

FIGURE 1

(A) Magnetic resonance imaging at the first visit. Bone metastasis was observed at Th11. (B) Computed tomography at the first visit. A 25‐mm renal tumor suggestive of renal cell carcinoma was found in the proximity of the renal hilum. (C) Positron emission tomography‐computed tomography at the first visit. A 12‐mm bone metastasis was detected in the left ilium. (D) Histopathological images of Th11; hematoxylin and eosin (HE) staining, 100×. The figure shows clear cell carcinoma consistent with renal cancer metastasis. (E) The left renal tumor shrunk after systemic treatment with a tyrosine kinase inhibitor (TKI). (F) Histologic examination of the renal tumor after TKI therapy, HE, 200×. This figure shows clear cell renal cell carcinoma with nests of clear cells surrounded by intricately branching vascular septa. Given that nucleoli are inconspicuous at high magnification, this tumor was diagnosed as Fuhrman grade 2. (G) Bone metastasis in the left ilium after systemic treatment with TKI. The size of the tumor decreased to 8 mm, with very weak accumulation observed on fluorodeoxyglucose‐positron emission tomography.

FIGURE 2

(A) Bone metastasis of the left ilium upon re‐enlargement. (B) Fluorodeoxyglucose accumulation in the right pubic bone on positron emission tomography‐computed tomography. (C) Pathology of the left iliac lesion; hematoxylin and eosin staining, 100×. The figure shows metastases of renal carcinoma, which invaded while destroying the trabeculae of the ilium.

FIGURE 3

(A) Computed tomography showing enlarged lymph nodes in the right axilla. (B) Magnetic resonance imaging showing a subcutaneous tumor in the right thigh. (C) Right axillary lymph node; hematoxylin and eosin staining, 20×. Lymph nodes were destroyed by the metastasis of the renal tumor. (D) Subcutaneous tumor of the right thigh; hematoxylin and eosin staining, loupe. Spherical metastases are seen within the subcutaneous adipose tissue.

FIGURE 4

Timeline that shows the relationship between the clinical condition and the course of treatment from the first visit to today.