Extension code 45 Pericolic fat extension to adjacent connective tissue
Extension code 46 Adherent to but not involving other structures
Code 45 indicates that the tumor has gone through all layers of the wall and into pericolic fat. Code 46 indicates that the tumor is adherent to other organs or structures but is not microscopically involved. The attachment may be viewed by imaging or surgical observation, but there is no pathologic evidence of invasion of the other organ.