Table 1.
Summarized description of the Karolinska tumor cohort and immunohistochemical staining outcomes of informative cases
| Chromogranin A | Synaptophysin | ISL1 | INSM1 | Secretagogin | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Tumor type | No. of cases | Positive | Negative | Positive | Negative | Positive | Negative | Positive | Negative | Positive | Negative |
| Pancreatic NEN | 32 | 30 | 2 | 31 | 0 | 30 | 2 | 22 | 0 | 8 | 2 |
| Small intestinal NEN | 25 | 25 | 0 | 24 | 0 | 0 | 25 | 16 | 1 | 15 | 2 |
| NEN CUP | 20 | 16 | 4 | 20 | 0 | 12 | 8 | 6 | 3 | 4 | 3 |
| Colorectal NEN | 14 | 10 | 4 | 14 | 0 | 11 | 3 | 8 | 1 | 7 | 0 |
| Pheo/paraganglioma | 9 | 9 | 0 | 9 | 0 | 9 | 0 | 7 | 0 | 1 | 5 |
| Appendiceal NEN | 6 | 6 | 0 | 6 | 0 | 1 | 5 | 5 | 0 | 5 | 0 |
| Merkel cell carcinoma | 4 | 3 | 0 | 4 | 0 | 4 | 0 | 1 | 0 | 1 | 0 |
| Duodenal NEN | 4 | 4 | 0 | 3 | 0 | 4 | 0 | 3 | 0 | 2 | 1 |
| Gastric NEN | 3 | 2 | 1 | 3 | 0 | 3 | 0 | 0 | 1 | Nd | Nd |
| Lung NEN | 3 | 3 | 0 | 3 | 0 | 3 | 0 | 2 | 0 | 2 | 0 |
| Esophageal NEN | 2 | 2 | 0 | 2 | 0 | 1 | 1 | 0 | 1 | 0 | 1 |
| NAME | 2 | 0 | 2 | 2 | 0 | 2 | 0 | 2 | 0 | Nd | Nd |
| Cervical NEN | 2 | 0 | 2 | 2 | 0 | 2 | 0 | Nd | Nd | Nd | Nd |
| Renal NEN | 2 | 2 | 0 | 2 | 0 | 2 | 0 | 1 | 0 | 1 | 0 |
| Prostatic NEN | 2 | 2 | 0 | 1 | 0 | 1 | 1 | Nd | Nd | Nd | Nd |
| Parathyroid lesions | 2 | Nd | Nd | Nd | Nd | 0 | 2 | 0 | 2 | 0 | 1 |
| NEN in teratoma | 2 | 2 | 0 | 2 | 0 | 2 | 0 | Nd | Nd | Nd | Nd |
| MTC | 2 | 2 | 0 | 1 | 0 | 2 | 0 | 2 | 0 | 2 | 0 |
| Pancreatic MiNEN | 1 | 1 | 0 | 1 | 0 | 1 | 0 | Nd | Nd | Nd | Nd |
| Urinary bladder NEN | 1 | 1 | 0 | 1 | 0 | 1 | 0 | Nd | Nd | Nd | Nd |
| Olfactory neuroblastoma | 1 | 1 | 0 | 1 | 0 | 0 | 1 | 1 | 0 | 1 | 0 |
| Non-NEN* | 22 | 3 | 17 | 8 | 11 | 6 | 16 | 2 | 5 | 0 | 5 |
NEN, neuroendocrine neoplasia; CUP, cancer of unknown primary; pheo, pheochromocytoma; NAME, neuroendocrine adenoma of the middle ear; MTC, medullary thyroid carcinoma; MiNEN, mixed neuroendocrine non-neuroendocrine neoplasia; Positive, focal or diffuse staining; Negative, absence of staining; Nd, not determined
*Non-NENs were initially suspected to be NEN based on histological features and therefore included in the study as controls. Positive staining in these tumors was almost always focal and occurred in 1–29% of tumor cells