Table 2.
Microscopic features of high-grade pancreatic neuroendocrine neoplasms
| Case | PDNEC subtype | MI | Ki-67 (%) | Ki-67 distribution | Low-grade component | Organoid growth pattern | Solid growth | Regular vascular patterns | Necrosis | Frequent apoptosis | Marked nuclear atypia | Macronucleoli | Ample cytoplasm |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| G3-NET-1 | - | 7 | 23.9 | Homo | – | Gyriform, trabecular | – | + | Geographic | – | – | + | + |
| G3-NET-2 | - | 4 | 22.7 | Hetero | + | Trabecular | – | + | - | – | – | – | + |
| G3-NET-3 | - | 8 | 24.9 | Hetero | + | Trabecular | + | + | - | – | – | + | + |
| G3-NET-4 | - | 21 | 14.2 | Homo | – | Nested | – | + | - | – | – | – | + |
| G3-NET-5 | - | 13 | 23.3 | Hetero | – | Nested, trabecular | – | + | Punctate | + | + | + | + |
| G3-NET-6 | - | 26 | 16.0 | Homo | – | Trabecular | + | + | Geographic | – | + | + | + |
| G3-NET-7 | - | 20 | 21.0 | Homo | + | Trabecular | – | + | Geographic | – | – | – | + |
| G3-NET-8 | - | 16 | 34.4 | Hetero | + | Trabecular | – | + | Punctate | – | + | – | + |
| PanNEC-1 | LC | 86 | 50.5 | Homo | – | Trabecular | – | + | Punctate | + | + | + | + |
| PanNEC-2 | SC | 23 | 40.5 | Homo | – | - | + | – | Punctate | + | + | + | – |
| PanNEC-3 | SC | 26 | 77.8 | Homo | – | Trabecular | + | – | Geographic | + | + | – | – |
| PanNEC-4 | LC | 35 | 73.6 | Homo | – | Nested | + | – | Punctate | + | + | + | + |
| PanNEC-5 | SC | 24 | 57.0 | Homo | – | - | + | – | - | + | + | + | – |
| PanNEC-6 | LC | 21 | 40.9 | Homo | – | - | + | – | - | – | + | + | + |
| PanNEC-7 | SC | 15 | 66.8 | Homo | – | Trabecular | + | – | Punctate | + | + | + | – |
PDNEC, poorly differentiated neuroendocrine carcinoma; MI, mitotic index, per 10 high-power fields (×400 magnification); NET, neuroendocrine tumor; PanNEC, pancreatic neuroendocrine carcinoma; LC, large cell PanNEC; SC, small cell PanNEC; Homo, homogeneous; Hetero, heterogeneous.