A Case of Metachronous Prostate Adenocarcinoma and Chromophobe Renal Cell Carcinoma in a Nigerian Male Patient: Diagnostic and Therapeutic Challenges.

Prostate adenocarcinoma and chromophobe renal cell carcinoma (ChRCC) are two distinct urologic malignancies with different prognoses and treatment approaches. The occurrence of both tumors in the same individual is highly unusual. We describe the case of a 69-year-old man with a long-standing history of hypertension who had previously undergone prostatectomy for benign prostatic hyperplasia. In 2022, he re-presented with recurrent lower urinary tract symptoms. Biopsy confirmed acinar adenocarcinoma of the prostate (Gleason 4+3), and magnetic resonance imaging (MRI) staged the disease as T3aN0M0. He was treated with high-dose-rate (HDR) brachytherapy followed by external beam radiotherapy (EBRT). Two years later, a right renal mass was detected. While the initial histology favored oncocytoma, immunohistochemistry revealed strong cytokeratin (CK)7 expression with focal CD117 staining, confirming the eosinophilic subtype of ChRCC. This case illustrates the importance of thorough histopathologic work-up of renal lesions, the diagnostic value of immunohistochemistry, and the need for careful follow-up in patients with complex urologic histories.