Table 1 Staging system for neuroendocrine tumor of the ampulla of Vater

Grade 1

<2 mitoses/10 HPF and <3% Ki–67

Grade 2

2–20 mitoses/10 HPF or 3–20% Ki–67

Grade 3

>20 mitoses/10 HPF or >20% Ki–67

TNM staging system

ENETS (2006)

UICC (7th edition, 2009)

T – primary tumor

Primary tumour cannot be assessed

No evidence of primary tumour

Invasion of lamina propria or submucosa and size ≤ 1 cm

Limited to ampulla of Vater or sphincter of Oddi

Invasion of muscularis propria or size > 1 cm

Invasion of the duodenum wall

Invasion of the pancreas or retroperitoneum

Invasion of the pancreas

Invasion of the peritoneum or other organs

Invasion in peripancreatic soft tissues or other adjacent organs or structures

N – regional lymph nodes

Regional lymph nodes cannot be assessed

No regional lymph node metastasis

Regional lymph node metastasis present

M – distant metastasis

Distant metastasis cannot be assessed

No distant metastasis

Distant metastasis present