Solid-pseudopapillary Neoplasm of the Pancreas
Supplemental Studies
Histochemistry
- Mucin stain negative
- Glycogen negative
- PASd positive intra and extracellular globules may be present
Immunohistology
| CD99 paranuclear dots | positive |
| Alpha 1 antitrypsin | positive |
| Alpha 1 antichymotrypsin | positive |
| Neuron specfic enolase | positive |
| Vimentin | positive |
| Progesterone receptor | positive |
| Beta-catenin | positive |
| CD10 | positive |
| CD56 | positive |
| FLI-1 | positive |
| Galectin 3 | positive |
| CD117 | positive |
| Keratin | variable |
| Synaptophysin | 50% |
| CD34 | negative |
| Estrogen receptor | negative |
| Chromogranin | negative |
- One report describes paranuclear dot like staining seen in solid-pseudopapillary tumor but not in neuroendocrine tumors or adenocarcinoma (Guo 2012)
- Other neoplasms have membrane or diffuse cytoplasmic staining
- If confirmed, this may be a very useful marker
- Alpha 1 antitrypsin and antichymotrypsin may identify only scattered cells, but they should be intensely stained
- Keratin usually negative or at most focally positive
- One report on the use of claudins
| Claudin 5 | Claudin 7 | |
|---|---|---|
| Solid Pseudopapillary Tumor | Strong membrane positive | Membrane negative, occasional cytoplasm |
Endocrine Tumor |
Membrane negative | Membrane positive |
| Acinar cell carcinoma | Membrane negative | Membrane positive |
| Pancreatoblastoma | Membrane negative | Membrane positive |
Molecular Genetics
- EWS/FLI-1 translocation not present even though FLI-1 positive by immunohistochemistry
