CS Extension

Notes

**Note 1**: AJCC does not include a Tis category for Neuroendocrine Tumors (NET) of the ampulla of Vater. Extension code 000 is mapped to TX for AJCC stage and in situ Summary Stage. **Note 2**: The assignment of the T1 and T2 categories for NETs of ampulla of Vater is based on tumor size. A physician's statement of the T category may be used to code both CS Tumor Size and/or CS Extension if this is the only information in the medical record regarding one or both of these fields. However the two fields are coded independently; for example, the record may document size but not extension. Use codes 310, 430, 600, and 810 as appropriate to code CS Extension based on a statement of T when no other extension information is available. **Note 3**: Use code 300 for localized tumor only if no information is available to assign code 100 or 430.
Code Description AJCC 7 T AJCC 6 T Summary Stage 1977 T Summary Stage 2000 T
000 In situ, intraepithelial, noninvasive TX Tis IS IS
100 Invasive tumor confined/limited to ampulla of Vater or extending to sphincter of Oddi Extension Size AJCC7 T1 L L
300 Localized, NOS Extension Size AJCC7 T1 L L
310 Stated as T1 with no other information on extension Extension Size AJCC7 T1 RE RE
420 Duodenal wall Extension Size AJCC7 T2 RE RE
430 Stated as T2 with no other information on extension Extension Size AJCC7 T1 L L
520 Pancreas T3 T3 RE RE
550 Retroperitoneum
Peripancreatic soft tissues		 T3 T3 D D
600 Stated as T3 with no other information on extension T3 T3 RE RE
610 Visceral peritoneum (serosa) T4 T4 RE RE
620 Common bile duct T4 T4 RE RE
650 Extrahepatic bile ducts other than common bile duct or sphincter of Oddi T4 T4 RE RE
700 Extension to other adjacent organs or tissues:
Blood vessels (major):
Hepatic artery
Portal vein
Gallbladder
Hepatic flexure
Lesser omentum
Liver including porta hepatis
Stomach, NOS:
Distal
Transverse colon		 T4 T4 RE RE
750 Stomach, proximal T4 T4 RE D
760 (620 to 750) + 550 T4 T4 D D
780 OBSOLETE DATA CONVERTED V0203
See code 810

Stated as T4, NOS		 ERROR: ERROR: ERROR: ERROR:
800 Further contiguous extension:
Other adjacent organs		 T4 T4 D D
810 Stated as T4 with no other information on extension T4 T4 RE RE
950 No evidence of primary tumor T0 T0 U U
999 Unknown extension
Primary tumor cannot be assessed
Not documented in patient record		 TX TX U U
- For CS Extension codes 100-430 ONLY, the T category for AJCC 7 staging is assigned based on the value of CS Tumor Size, as shown in the Extension Size AJCC 7 Table for this schema.