Table 2.
Summary of Findings
| Serotonin Negative | Serotonin Positive | P value | ||
|---|---|---|---|---|
| Number | 38 | 14 | -- | |
| Median age (Range) | 57 (36–90) | 49 (23–66) | 0.046a | |
| Sex ratio M:F | 20:18 | 4:10 | 0.21b | |
| Median tumor size (Range) | 3.2 cm (1–7) | 2.3 cm (1–6) | 0.39a | |
| Tumor locationc: | Head | 23 of 37 (62%) | 10 of 14 (71%) | 0.74b |
| Body or tail | 14 of 37 (38%) | 4 of 14 (29%) | ||
| Median mitoses per 10 HPF (Range) | 0.2 (0–11) | 0 (0–0.2) | <0.01i | |
| Average Ki-67 proliferation indexd | 5.48% | 3.34% | 0.17a | |
| Tumor grade (by Ki-67%)e: | G1 | 13 of 37 (35%) | 8 of 14 (57%) | 0.21b,f |
| G2 | 23 of 37 (62%) | 6 of 14 (43%) | ||
| G3 | 1 of 37 (3%) | 0 of 14 | ||
| Lymph node metastasesg | 25 of 34 (74%) | 4 of 13 (31%) | 0.016b | |
| Known distant metastasesh | 15 of 29 (52%) | 2 of 9 (22%) | 0.15b | |
| Large duct involvement | 15 of 37 (41%) | 11 of 13 (85%) | <0.01b | |
| Infiltrative growth | 32 of 38 (84%) | 14 of 14 (100%) | 0.17b | |
| Necrosis | 7 of 38 (18%) | 2 of 14 (14%) | 1b | |
| Perineural invasion | 26 of 38 (68%) | 7 of 14 (50%) | 0.33b | |
| Small vessel invasion | 20 of 37 (54%) | 4 of 14 (29%) | 0.13b | |
| Large vessel invasion | 3 of 38 (8%) | 1 of 14 (7%) | 1b | |
| Trabecular or trabecular-glandular architecture | 6 of 38 (16%) | 8 of 14 (57%) | <0.01b | |
| CDX2 positive | 9 of 33 (27%) | 5 of 12 (42%) | 0.47b | |
a
Student’s t-test, two-tailed.
b
Fisher’s exact test.
c
One case had no location recorded in the anatomic pathology report.
d
One serotonin-negative case had no tissue remaining for Ki-67 immunohistochemical staining.
e
G1 = <2%; G2 = 2–20%; G3 = >20%
f
G1 vs. G2/G3
g
Five cases had no lymph nodes submitted.
h
14 cases had no information on distant metastases.
i
Kruskal-Wallis equality-of-populations rank test