Ampulla of Vater
TNM staging of duodenal and ampullary neuroendocrine tumors (AJCC 8th edition)

Editor-in-Chief: Debra Zynger, M.D.
Raul S. Gonzalez, M.D.

Topic Completed: 1 May 2018

Minor changes: 12 February 2020

Copyright: 2003-2019,, Inc.

PubMed Search: TNM staging ampullary neuroendocrine tumors

Raul S. Gonzalez, M.D.
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Cite this page: Gonzalez RS. TNM staging of duodenal and ampullary neuroendocrine tumors (AJCC 8th edition). website. Accessed May 24th, 2020.

Pathologic TNM staging of neuroendocrine tumors of the duodenum and ampulla of Vater, AJCC 8th edition
Definition / general
  • Well differentiated neuroendocrine tumors of the ampulla ("carcinoids") and of the duodenum are covered by this staging system
  • Not covered by this staging system are poorly differentiated neuroendocrine carcinomas at this location (use the adenocarcinoma staging system instead)
Essential features
  • AJCC 7th edition staging was sunset on December 31, 2017; as of January 1, 2018, use of the 8th edition is mandatory
  • Hormone secretion by the tumor (gastrin, somatotatin, etc.) is not incorporated into staging
  • "Carcinoid” is no longer an acceptable term
ICD coding
  • ICD-10: C7A.019 - Malignant carcinoid tumor of the small intestine, unspecified portion
Primary tumor (pT)
  • TX: primary tumor cannot be assessed
  • T1: tumor invades the mucosa or submucosa only and is ≤ 1 cm (duodenal tumors); tumor ≤ 1 cm and confined within the sphincter of Oddi (ampullary tumors)
  • T2: tumor invades the muscularis propria or is ≥ 1 cm (duodenal); tumor invades through sphincter into duodenal submucosa or muscularis propria or is ≥ 1 cm (ampullary)
  • T3: tumor invades the pancreas or peripancreatic adipose tissue
  • T4: tumor invades the visceral peritoneum (serosa) or other organ
  • Notes: Tis is not a valid category under AJCC 8th edition staging for these tumors
Regional lymph nodes (pN)
  • NX: Regional lymph nodes cannot be assessed
  • N0: No regional lymph node involvement
  • N1: Regional lymph node involvement

  • Notes: Regional lymph nodes include duodenal, hepatic, pancreatoduodenal, infrapyloric, gastroduodenal, pyloric, superior mesenteric and pericholedochal nodes
Distant metastasis (pM)
  • M0: No distant metastasis
  • M1: Distant metastasis
    • M1a: Metastasis confined to liver
    • M1b: Metastasis in at least one extrahepatic site (e.g., lung, ovary, nonregional lymph node, peritoneum, bone)
    • M1c: Both hepatic and extrahepatic metastases
  • r: recurrent tumor stage
Stage grouping
  • Stage I: T1 N0 M0
  • Stage II: T2 - T3 N0 M0
  • Stage III: T4 N0 M0
  •  any T N1 M0
  • Stage IV: any T any N M1

Registry data collection variables
  • Size of tumor
  • Maximum depth of invasion
  • Number of tumors
  • Lymph node status
  • Grade
  • Mitotic count
  • Ki67 labeling index
  • Perineural invasion
  • Lymphovascular invasion
  • Margin status
  • Functional status
  • Genetic syndrome
  • Location in duodenum
  • Type of surgery
  • Preoperative chromogranin A level
  • Preoperative pancreastatin level
  • Preoperative neurokinin level
  • Age of patient
  • Histologic variants
Histologic grade
  • Grading is not formally part of the staging system
  • Most pathologists use the ENETS / WHO grading criteria:
    • G1: mitotic rate < 2 per 10 high power fields and Ki67 rate < 3%
    • G2: mitotic rate 2 - 20 per 10 high power fields or Ki67 rate 3 - 20%
    • G3: mitotic rate > 20 per 10 high power fields or Ki67 rate > 20%
Histopathologic type
Board review style question #1
    Regarding neuroendocrine tumors of the ampulla, which T category in the 8th edition AJCC staging guide includes size as a factor?

  1. T1 only
  2. T1 and T2
  3. T1, T2, and T3
  4. T2, T3, and T4
Board review answer #1
B. T1 and T2

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