Small intestine & ampulla


Staging-duodenal & ampullary neuroendocrine tumors

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

Last author update: 10 December 2020
Last staff update: 1 April 2024 (update in progress)

Copyright: 2003-2024,, Inc.

PubMed Search: TNM staging ampullary neuroendocrine tumors

Raul S. Gonzalez, M.D.
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Cite this page: Gonzalez RS. Staging-duodenal & ampullary neuroendocrine tumors. website. Accessed April 15th, 2024.

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 style answer #1
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