Figure 6.

Comparison of chromophobe renal cell carcinoma (ChRCC) with renal oncocytoma (RO). Differential diagnosis between these entities is difficult since they overlap in origin and morphology. (A1–A4) cytokeratin 7 is highly intense and diffusely stained in ChRCC in contrast to RO showing perfect negativity. (B1–B3) CD10 is generally negative, but focally patch positive, which is ignored. (C1–C3) Alpha-methylacyl-CoA racemase is negative or patch positive. Epithelial membrane antigen (B4) and E-cadherin (C4) are diffusely positive both in ChRCC and RO. (D1–D4) c-kit staining is basically positive in both entities. (E1–E4) Hepatocyte nuclear factor-1β (HNF1β) staining is a highly useful immunomarker to rule out the possibility of ChRCC. Scale bars = 1 mm.