Solid-pseudopapillary Neoplasm of the Pancreas
Differential Diagnosis
| Well Differentiated Pancreatic Neuroendocrine (Islet Cell) Tumor |
Solid Pseudopapillary Neoplasm of the Pancreas |
| Lacks pseudopapillary architecture |
Frequent pseudopapillary architecture |
| Chromogranin usually strongly positive |
Chromogranin focal to negative |
| Keratin positive |
Keratin variable |
| Galectin 3 negative |
Galectin 3 positive (small numbers) |
| Vimentin, CD10 negative |
Vimentin, CD10 positive |
| Nuclear beta catenin negative |
Nuclear beta catenin positive |
| No PAS+ granules in cytoplasm |
PAS+ granules may be present |
| CD99 variable but not paranuclear dots |
CD99 paranuclear dots (one report) |
Solid pseudopapillary neoplasm may be synaptophysin positive
| Acinar Cell Carcinoma of the Pancreas |
Solid Pseudopapillary Neoplasm of the Pancreas |
| Predominantly male |
Overwhelmingly female |
| Granular PASd+ cytoplasm |
PASd+ only scattered globules |
| Beta-catenin/CD56/CD10 negative |
Beta-catenin/CD56/CD10 positive |
| BCL10, trypsin, chymotrypsin positive |
BCL10, trypsin, chymotrypsin negative |
| Alpha 1 antitrypsin negative |
Alpha 1 antitrypsin positive |
| Keratin positive |
Keratin variable |
| Usually infiltrative |
Usually circumscribed |
| Lacks pseudopapillary architecture |
Frequent pseudopapillary architecture |
| May have true lumens |
No true lumens |
| Frequently increased mitotic figures |
Infrequent mitotic figures |
| CD99 negative |
CD99 paranuclear dots (one report) |
Clear cell variant of solid pseudopapillary neoplasm is also reported to be glycogen negative
Clear cell variant of solid pseudopapillary neoplasm is also reported to be glycogen negative
