Pancreatic Intraepithelial Neoplasia

Grading / Staging / Report

Grading
- PanIN 1A
  - Flat
  - Tall columnar cells
  - Bland, basal nuclei
  - Abundant supranuclear mucin
- PanIN 1B
  - Micropapillary architecture or
  - Basally stratified architecture
  - Otherwise identical to PanIN 1A
- PanIN 2
  - Usually papillary but may be flat
  - Mild cytologic atypia
    - Loss of polarity
    - Nuclear crowding
    - Pseudostratification
    - Hyperchromasia
    - Mitotic figures rare, not atypical
  - No necrosis or cribriform architecture
- PanIN 3
  - Architectural atypia
    - Cribriform or
    - Budding off of small clusters of cells into lumen
    - Lumenal necrosis
      - Diagnostic if present
  - Significant cytologic atypia
    - Loss of nuclear polarity
    - Dystrophic (upside down) goblet cells
    - Prominent nucleoli
    - Frequent mitotic figures
      - May be atypical
Staging
- Not relevant unless invasive carcinoma is present
Report
- Grade
- Presence or absence of invasive carcinoma
  - Give type and size