AdenoCA of Colon : Pericolonic Tumor Deposits

Comments:
Pericolonic Tumor Deposits are defined as discrete tumor nodules in the pericolic/perirectal fat or adjacent mesentery within the lymph drainage area of the primary tumor without identifiable lymph node tissue or identifiable vascular or neural structures.

They usually have irregular outlines and are found away from the leading edge of the tumor. They are seen in approximately 10% of colon and rectal cancers. They are a negative prognostic factor and considered equivalent to positive nodes. They are associated with poor prognosis.

The strength of pericolic tumor deposits as an adverse prognostic indicator has led to the introduction of N1c category. It is defined as – no regional lymph node metastases but presence of tumor deposits in the subserosa, mesentery, or nonperitonealized pericolic or perirectal/mesorectal tissues. The number of tumor deposits is not added to the number of positive regional lymph nodes if one or more lymph nodes contain cancer.