AMACR and papillary renal cell carcinoma: On the other hand, AMACR (Alpha-methylacyl-CoA racemase) is frequently positive in Xp11 translocation renal cell carcinomas, as well as in papillary renal cell carcinomas, but CK7 is typically negative in Xp11 translocation renal cell carcinomas and positive in papillary renal cell carcinomas.