Genetic mutations in accordance with a low malignant potential tumour are not demonstrated in clear cell papillary renal cell carcinoma.

Clear cell papillary renal cell carcinoma (CCPRCC) cases were evaluated for mutations on the following genes: KRAS, NRAS, BRAF, PIK3CA, ALK, ERBB2, DDR2, MAP2K1, RET and EGFR. Four male and three female patients of age 42-74 years were evaluated. All cases were incidentally detected by ultrasound and ranged 1.8-3.5 cm. Microscopic examination showed variably tubulopapillary, tubular acinar, cystic architecture and the characteristic linear arrangement of nuclei. The cells were reactive with CK7 (strong), CA IX (cup-shape) and 34 β E12. CD10, AMACR/RACEMASE and GATA3 were negative. There were no mutations on any of the investigated genes. This preliminary observation supports the concept that CCPRCC might be indeed an indolent tumour worth it to be named as clear cell papillary neoplasm of low potential.