Duodenum (Psammomatous) Somatostatinoma
Supplemental Studies
- Somatostatin stain diffusely positive
- (Scattered somatostatin positive cells may be seen in other neuroendocrine neoplasms)
- May also have focal cells positive for calcitonin, pancreatic polypeptide, ACTH, gastrin, serotonin
- Synaptophysin usually positive
- Chromogranin variable, may be negative
- Argyrophil variable, argentaffin negative
- PASd stains luminal border and secretions but not cytoplasm
