Table 1 Histopathological characteristics of neuroendocrine carcinomas of the small intestine[5]
Histotype | Mitoses | Ki67 index | Nuclear atypia | Necrosis | Immunoreactivity |
|---|---|---|---|---|---|
Well differentiated (G1- carcinoids) | < 2/10 HPF | < 2% | Absent | Absent | Synaptophysin (+) |
Chromogranin A (+) | |||||
Moderately differentiated (G2) | 2–20/10 HPF | 3-20% | May be present | May be present | Synaptophysin (+) |
Chromogranin A (+) | |||||
Poorly differentiated (G3 - neuroendocrine carcinoma) | > 20/10 HPF | > 20% | Usually present | Usually present | Synaptophysin (+) |
Chromogranin A (−/+) |