Combined Clear Cell Renal Cell Carcinoma and Chromophobe Renal Cell Carcinoma: A Case Report.

Renal cell carcinoma (RCC) is a diverse array of cancers arising from renal tubular epithelial cells. RCC presenting with distinct morphological subtypes, such as the simultaneous presence of chromophobe RCC (chRCC) and clear cell RCC (ccRCC) lesions within the same kidney, is rare. We present the case of a 79-year-old female with a history of breast cancer who presented to our facility with right flank pain. Further investigations using CT of the abdomen and pelvis revealed a Bosniak type 4 cyst with a mural nodule in the right kidney. Furthermore, another well-defined, solid lesion measuring 2.8 × 2.6 cm was observed in the same area. The patient underwent a right radical nephrectomy. The macroscopic examination of the kidney revealed the presence of three cysts, with the largest measuring up to 7.5 cm. Moreover, a distinctly demarcated, golden-yellow, solid mass was discerned in the superior pole of the kidney. The mass showed a heterogeneous cut surface with solid and cystic components, measuring 2.8 × 2.6 × 2.0 cm. A less extensive but well-defined, uniform tan mass was also identified within the wall of the largest cyst, which measured 1.2 × 1.0 × 0.7 cm. At this point, the diagnosis of ccRCC and chRCC was established.