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Cite this page: Gonzalez RS. Staging-duodenal & ampullary neuroendocrine tumors. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/ampullatnmstaging.html. Accessed April 3rd, 2025.
Definition / general
- Well differentiated neuroendocrine tumors of the ampulla (carcinoids) and 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
- AJCC 9th edition was released in 2023, with minimal changes from the 8th edition
- Hormone secretion by the tumor (gastrin, somatostatin, etc.) is not incorporated into staging
Terminology
- 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 is ≤ 1 cm in greatest dimension and confined within the sphincter of Oddi (ampullary tumors)
- T2: tumor invades the muscularis propria or is > 1 cm (duodenal tumors); tumor invades through sphincter into duodenal submucosa or muscularis propria or is > 1 cm in greatest dimension (ampullary tumors)
- 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 tumor involvement of regional lymph node(s)
- N1: tumor involvement of regional lymph node(s)
Notes:
- Regional lymph nodes include duodenal, hepatic, pancreatoduodenal, infrapyloric, gastroduodenal, pyloric, superior mesenteric and pericholedochal nodes
Prefixes
- c: clinical
- p: pathological
- yc: posttherapy clinical
- yp: posttherapy pathological
Primary tumor suffix
- (m): multiple synchronous primary tumors
Regional lymph nodes suffix
- (f): fine needle aspiration (FNA) or core needle biopsy
AJCC prognostic stage groups
| Stage I: | T1 | N0, NX | M0
|
| Stage II: | T2, T3 | N0 | M0
|
| Stage III: | T4 | N0 | M0
|
| Stage III: | any T | N1 | M0
|
| Stage IV: | any T | any N | M1
|
Prognostic tumor characteristics
- Ki67 index
- Mitotic count
- Functionality
- Location of the duodenum
Registry data collection variables
- Age of patient
- Functional status (yes / no; if yes, then list type of syndrome)
- Genetic syndrome (yes / no; if yes, then list type of syndrome)
- Type of procedure / surgery
- Location in duodenum
- Size of tumor
- Tumor focality (unifocal or multifocal, number of tumors)
- Histologic variants
- Grade (based on Ki67 and mitotic count): G1, G2, G3, unknown
- Mitotic count (value; unknown)
- Ki67 labeling index (value; unknown)
- Maximum depth of invasion
- Invasion into adjacent organs (yes / no; if yes, then list which organ)
- Perineural invasion
- Lymphovascular invasion
- Tumor necrosis
- Margin status
- Lymph node status (including number of nodes assessed and number of positive nodes)
Histologic grade (G)
- G1: mitotic rate < 2 per 2 mm2 and Ki67 < 3%
- G2: mitotic rate 2 - 20 per 2 mm2 or Ki67 3 - 20%
- G3: mitotic rate > 20 per 2 mm2 or Ki67 > 20%
Histopathologic type
- Neuroendocrine tumor, NOS
- Neuroendocrine tumor, grade 1
- Neuroendocrine tumor, grade 2
- Neuroendocrine tumor, grade 3
- Gastrinoma (G cell neuroendocrine tumor)
- Somatostatinoma, NOS (D cell neuroendocrine tumor)
- Enterochromaffin cell (EC cell) neuroendocrine tumor
- Composite gangliocytoma / neuroma and neuroendocrine tumor
Residual tumor (operative factor)
- R0: complete resection, margins histologically negative, no residual tumor left after resection
- R1: incomplete resection, margins histologically involved, microscopic tumor remains after resection of gross disease (relevant to resection margins that are microscopically involved by tumor)
- R2: incomplete resection, margins involved or gross disease remains
Board review style question #1
Regarding neuroendocrine tumors of the ampulla, the 9th edition AJCC staging guide includes size as a factor for which of the following pT categories?
- pT1 only
- pT1 and pT2
- pT1, pT2 and pT3
- pT2, pT3 and pT4
Board review style answer #1
B. pT1 and pT2. These are the 2 pT categories in AJCC staging of ampullary neuroendocrine tumors that involve size criteria. Answer A is incorrect because the category pT2 also includes size as a factor. Answers C and D are incorrect because pT3 and pT4 do not include size criteria.
Comment Here
Reference:
Staging - duodenal & ampullary neuroendocrine tumors Board review style question #2
Which of the following is true regarding staging of duodenal / ampullary well differentiated neuroendocrine tumors?
- Invasion of an ampullary tumor into but not through the duodenal submucosa is considered pT1 disease
- pT2 criteria are different for duodenal tumors and ampullary tumors
- pT3 criteria are different for duodenal tumors and ampullary tumors
- Size > 5 cm indicates pT4 disease
Board review style answer #2
B. pT2 criteria are different for duodenal tumors and ampullary tumors. They have the same size criterion but differ in which layers / structures of the bowel wall can be involved. Answer A is incorrect because invasion of an ampullary tumor into but not through the duodenal submucosa would be considered pT2 disease. Answer C is incorrect because pT3 criteria are the same for duodenal and ampullary tumors. Answer D is incorrect because pT4 disease requires the involvement of the visceral peritoneum or an adjacent organ.
Comment Here
Reference:
Staging - duodenal & ampullary neuroendocrine tumors
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