Background: Bilateral asynchronous renal cell carcinoma (RCC) is infrequent. Immunotherapy is the first-line treatment for advanced RCC not controlled by locoregional therapy. Viscum album extracts (VAE) have been shown to improve quality of life as well as immunological and antineoplastic properties in different types of cancers. Case Report: A 67-year-old man was diagnosed with Fuhrman grade 3/4 RCC, stage pT1bN0M0 in the right kidney. During the subsequent 6 years, he underwent a right nephrectomy and two metastasectomies (lung). Then an RCC lesion of the left kidney was detected. The patient refused a second nephrectomy and was treated solely with high-dose intravenous and subsequent subcutaneous VAE. A central necrotic area and a peritumoral halo were seen on an ultrasound follow-up from month 7. The patient showed no further progression of RCC during the next 2.5 years. Conclusion: As far as we are aware of, this is the first report of a patient with metastatic RCC with an RCC lesion of the second kidney treated solely with high-dose intravenous and subcutaneous VAE, associated with 2.5 years of progression-free survival and a good quality of life. The use of VAE in RCC should be carefully documented and published to determine future research.

Key Words: Renal cell carcinoma, clear-cell, Viscum album, bilateral, asynchronous.

Citation: Reynel, M., Villegas, Y., Kiene, H., Werthmann, P. G., & Kienle, G. S. (2019). Bilateral Asynchronous Renal Cell Carcinoma With Lung Metastases: A Case Report of a Patient Treated Solely With High-dose Intravenous and Subcutaneous Viscum album Extract for a Second Renal Lesion. Anticancer Research, 39(10), 5597–5604. https://doi.org/10.21873/anticanres.13754