CD163 and papillary renal cell carcinoma: Behnes et al [31] found that nearly all macrophages in papillary renal cell carcinoma (RCC) type II expressed CD163, whereas in type I papillary RCC, less than 30% of macrophages expressed CD163, which might explain why the prognosis of papillary RCC type II was worse than that of type I. Our study showed that the frequency of CD163+ macrophages was higher in MPE than those in NMPE.