KRAS and in situ carcinoma: A previous study showed a very high frequency of KRAS mutation (93%) in flat adenomas with a tubulovillous architecture.34 We would agree with the suggestion that KRAS mutation is linked with the development of villous change and does not influence adenoma growth in an independent manner.6 In this study, high-grade dysplasia was diagnosed only when it amounted to carcinoma in situ.