Acinar Cell Cystadenoma of the Pancreas
Definition
- Benign cystic lesion of the pancreas lined by cells exhibiting acinar differentiation
Alternate/Historical Names
- Acinar cystic transformation (may be a better name, as the lesion is not clonal (Singhi))
Diagnostic Criteria
- Wide range of cystic architectural patterns
- Unilocular to multilocular
- Cysts may range from minimally dilated acini to prominent cysts
- Mean size 7 cm, microscopic up to 15 cm
- Solitary to multiple
- One diffuse case reported
- Intracystic nodules may be present
- Only rarely communicates with duct system
- Cysts predominantly lined by bland cells with acinar differentiation
- Moderate to abundant granular eosinophilic cytoplasm
- PAS positive diastase resistant
- Usually apical
- Basal cytoplasm may be basophilic
- Lining may be multilayered
- Lumenal cells may be attenuated
- Multiloculated lesions focally lined by patches of normal appearing ductal cells or squamous cells
- Moderate to abundant granular eosinophilic cytoplasm
- May form patches with acini
- May be associated with ducts lined by mucinous columnar epithelium / low grade PanIN
- Cytologically bland
- May have at most mild atypia
- Nucleoli present but small
- Mitotic figures, necrosis absent
- No invasion
- No solid acinar cell adenomas have been reported (see Acinar Cell Nodule)
Robert V Rouse MD
Department of Pathology
Stanford University School of Medicine
Stanford CA 94305-5342
Original posting, last update: 1/2/08, 12/28/13
