Supplementary Material for: Non-familial Bilateral Synchronous Renal Cell Carcinoma with Discordant Histology with Eventual Complete Response to Dual Immunotherapy

Bilateral synchronous renal cell carcinoma (RCC) is rare, especially in sporadic rather than familial cases. While immunotherapy has improved prognosis, RCC remains a diagnosis with significant morbidity and mortality, particularly pronounced in patients with sarcomatoid RCC (sRCC). We describe a case of a patient with bilateral, synchronous, non-familial RCC, with and without sarcomatoid features and differing genetic markers, who demonstrated a pathologic response after neoadjuvant nivolumab and ipilimumab. The patient then had radical left nephrectomy and partial right nephrectomy followed by adjuvant nivolumab and cabozantinib, after which the patient had no evidence of disease. Our patient’s illustrative case shows the potential therapeutic value of immunotherapy even in sRCC, the disease’s most aggressive clinical subtype.