|  | Differentiation of adenocarcinoma |  | |
---|---|---|---|---|
 |  | intestinal | pancreatobiliary | p-valuea |
Tumour origin | ampulla | 28 | 13 | < 0.001 |
 | duodenum | 16 | 0 |  |
 | distal bile duct | 1 | 16 |  |
 | pancreas | 2 | 38 |  |
pT stage | pT1 | 10 | 2 | < 0.001 |
 | pT2 | 20 | 9 |  |
 | pT3 | 8 | 46 |  |
 | pT4 | 9 | 10 |  |
Lymph node status | N0 | 23 | 26 | 0.282 |
 | N1 | 24 | 41 |  |
Resection margin status | R0 | 40 | 34 | < 0.001 |
 | R1 | 7 | 33 |  |
Vessel involvement | free | 35 | 36 | 0.025 |
 | involved | 12 | 31 |  |
Perineural infiltration | no | 35 | 17 | < 0.001 |
 | yes | 12 | 50 |  |
Areas with poorly differentiated tumour | no | 39 | 32 | < 0.001 |
 | yes | 8 | 35 |  |
Tumour size (maximum tumour diameter) | small (≤ 2.5 cm) | 31 | 35 | 0.108b |
 | large (> 2.5 cm) | 16 | 32 |  |