Table 1 Clinicopathologic features of the 9 cases of ISMC
| Â | Case 1 | Case 2 | Case 3 | Case 4 | Case 5 | Case 6 | Case 7 | Case 8 | Case 9 |
|---|---|---|---|---|---|---|---|---|---|
Age, sex | 74, F | 66, M | 56, F | 66, F | 82, F | 77, F | 76, M | 71,M | 44, M |
Colorectal site | Ascending colon | Ascending colon | Cecum | Sigmoid colon | Transverse colon | Hepatic flexure | Cecum | Ascending colon | Hepatic flexure |
Tumor size | 2.1 × 1.5x0.5 | 3.0 × 2.5x0.8 | 5.5 × 5.0x1.2 | 5.0 × 3.0x2.5 | 15.4 × 10.0x3.1 | 4.5 × 2.6x1.4 | 3.6 × 3.5x2.5 | 5.1 × 4.7x3.2 | 6.0 × 5.0x2.7 |
% of ISMC | 90% | 60% | 30% | 20% | 20% | 20% | 15% | 15% | 10% |
Pre-existing lesion | TA | None | TVA | None | None | None | None | None | None |
LVI | Present | Present | Present | Present | Present | Present | Present | Present | Present |
PNI | Absent | Absent | Absent | Present | Absent | Absent | Present | Absent | Present |
Tumor stage | T1N0M0 | T3N1bM0 | T3N1aM0 | T4aN2bM0 | T4aN2aM0 | T3N2bM0 | T4bN2bM1a | T4bN2aM1 | T4aN2bM0 |
Appendix | Present; normal | Present; normal | Present; normal | Present; normal | Present; normal | Appendix with SSP | Remote appendectomy | Remote appendectomy | Present; normal |
MLH1 | Loss | Loss | Loss | Intact | Loss | Loss | Intact | Intact | Intact |
MSH2 | Intact | Intact | Intact | Intact | Intact | Intact | Intact | Intact | Intact |
MSH6 | Intact | Intact | Intact | Intact | Intact | Intact | Intact | Intact | Intact |
PMS2 | Loss | Loss | Loss | Intact | Loss | Loss | Intact | Intact | Intact |
KRAS | No mutation | No mutation | No mutation | No mutation | No mutation | No mutation | Â | Â | No mutation |
NRAS | No mutation | No mutation | No mutation | No mutation | No mutation | No mutation | Â | Â | No mutation |
BRAF | BRAF V600E (c.1799 T > A) mutation | BRAF V600E (c.1799 T > A) mutation | No mutation | No mutation | BRAF V600E (c.1799 T > A) mutation | BRAF V600E (c.1799 T > A) mutation |  |  | No mutation |
PIK3CA | PIK3CA mutation (p.Glu81Lys) | PIK3CA mutation (p.Glu81Lys | No mutation | No mutation | PIK3CA mutation (p.Glu54Lys) | No mutation | Â | Â | PIK3CA mutation (p.Glu81Lys) |
Post-surgical treatment & Follow up | No chemotherapy. 12 months. Alive with no disease | Chemotherapy. 27 months. Alive with no disease | Chemotherapy. 30 months. Alive with no disease | Chemotherapy. 22 months. Alive with no disease | Declined chemotherapy. 18 months. Alive with disease | Chemotherapy. 21 months. Alive with disease | Chemotherapy. 27 months. Alive with disease | Chemotherapy. 7 months. Died of disease | Chemotherapy. 32 months. Alive with no disease |