Characteristics of individuals and tumours with MSI-H tumours but with no mismatch repair defect, as determined by immunostaining (false negative IHC)
| ID | Age | Sex | AC | Stage | Site | IEL | Mucin | Grade | p53 | K-ras |
| FN1 | 62 | F | No | I | AsC | + | No | Mod | Wild | Mut |
| FN2 | 62 | M | No2-150 | II | AsC | + | Yes | Poor | Wild | Wild |
| FN3 | 67 | F | No | II | TC | − | No | Mod | Mut | Wild |
| FN4 | 77 | F | No | II | TC | − | No | Mod | Mut | Wild |
| FN5 | 83 | F | No | IV | Caecum | + | Yes | Poor | Wild | Wild |
| FN6 | 84 | F | No | IV | SC | − | No | Poor | Wild | Wild |
AC, Amsterdam criteria, IEL, intraepithelial lymphocytes, Mut, mutant, TC, transverse colon, AsC, ascending colon, SC, sigmoid colon; MSI-H, high level of microsatellite instability.
↵2-150 This patient had three first degree relatives with either breast or gastric carcinoma.