A tumor deposit is defined as a discrete nodule of cancer in pericolic/perirectal fat or in adjacent mesentery (mesocolic or rectal fat) within the lymph drainage area of the primary carcinoma, without identifiable lymph node tissue or identifiable vascular structure.

The presence of tumor deposits is a Registry Data Collection Variable in AJCC. It was previously collected as Colon and Rectum CS SSF# 4.

Item #	Length	Source of Standard	Year Implemented	Version Implemented	Year Retired	Version Retired
3934	2	NAACCR	2018	18

00	No tumor deposits
01-99	01-99 Tumor deposits (Exact number of Tumor Deposits)
X1	100 or more Tumor Deposits
X2	Tumor Deposits identified, number unknown
X8	Not applicable: Information not collected for this case (If this information is required by your standard setter, use of code X8 may result in an edit error.)
X9	Not documented in medical record Cannot be determined by the pathologist Pathology report does not mention tumor deposits No surgical resection done Tumor Deposits not assessed or unknown if assessed

Each Site-Specific Data Item (SSDI) applies only to selected primary sites, histologies, and years of diagnosis. Depending on applicability and standard-setter requirements, SSDIs may be left blank.