The intersection of histologies: navigating the complexity of a renal collision tumor

Renal cell carcinoma is a heterogeneous group of renal tumors characterized by several histological subtypes. Herein, we discuss an unusual case of a 55-year-old male who presented as a consultation to our urology clinic with an incidentally found renal mass. After shared decision making patient proceeded with a Robotic Assisted Laparoscopy (RAL) left sided partial nephrectomy. Final pathology confirmed the presence of high nuclear grade mixed clear cell and papillary renal cell carcinoma (RCC) of the left kidney (pT3aN0M0). This case elucidates a very rare incidence of a patient seen to have a collision tumor, and furthermore demonstrates guideline-based treatment.