Abstract
Dual malignancies involving clear cell renal cell carcinoma (ccRCC) and chronic lymphocytic leukemia (CLL) present a rare and challenging clinical scenario. This report describes a 75-year-old male with a history of monoclonal B-cell lymphocytosis (MBL) that progressed to CLL, later complicated by the development of ccRCC. Following neoadjuvant pembrolizumab, he underwent left nephrectomy with pathology confirming renal cell carcinoma (RCC). Subsequent imaging revealed a recurrent renal bed nodule, and a retroperitoneal lymph node biopsy demonstrated concurrent CLL and metastatic RCC. Our report aims to enhance recognition and management strategies for such complex dual malignancies.