Code 1: Localized

  • Malignancy limited to organ of origin
  • Can be widely invasive or have spread within the organ of origin
  • Basement membrane has been invaded
  • No spread beyond boundaries of the organ

The illustration below shows a tumor that has invaded past the basement membrane below the surface epithelium of the organ into the parenchyma or stroma.

Illustration of a localized tumor with arrows identifying the epithelium of organ, basement membrane, parenchyma of organ, and a tumor that has invaded past the basement membrane below the surface epithelium of the organ into the parenchyma or stroma.

Source: Adapted from an illustration by Brian Shellito of Scientific American, as printed in Cancer in Michigan, The Detroit News, Nov. 1-2, 1998

It is important to know and recognize the names of different structures within the organ (such as lamina propria, myometrium, muscularis propria, for example) so that a description of invasion or involvement of these structures will not be interpreted as regional spread.

If the pathology reports, operative reports and other investigations show no evidence of spread, the tumor may be assumed to be localized (if in situ disease has been eliminated as possibility).

Updated: December 15, 2023