[The brand new trend of colorectal carcinoma pathology]

Japanese classification of colorectal carcinoma continues to develop several decades. In 2015, the Japanese Society for Cancer of the Colon and Rectum published the eighth edition of the general rules for clinical and pathological studies on cancer of the colon, rectum, and anus. The new Japanese classification of colorectal carcinoma based on new evidences including sessile serrated adenoma/polyp (SSA/P) of serrated polyp, budding, desmoplastic reaction, head/stalk invasion, submucosal invasion depth for early cancer, EX (extramural cancer deposit), and PN (perineural invasion) for advanced cancer. And recently molecular targeted therapy for anti EGFR has made rapidly progress in refractory advanced cancer. However, some issues still remain to be resolved in pathological diagnosis. We describe and discuss about assessment of pathological diagnosis for new therapy for colorectal carcinoma.