KRAS and invasive ductal breast carcinoma: In a study of microdissected samples from 20 intraductal papillary-mucinous tumors (IPMT) and 7 ductal adenocarcinoma, K-ras mutations were noted in 66.7% of peri-tumoral tissue and 62.5% of separate IPMT lesions, and at least one identical mutation was observed in the tumor and peritumoral tissue in all IPMT patients with those lesions [31].