Adenocarcinoma of the Stomach
Grading / Staging
Grading
- WHO gastric adenocarcinoma grading criteria
- Low grade
- Well differentiated – well formed glands
- In areas may be difficult to distinguish from benign atypia
- Moderately differentiated - may be combined with well as low grade
- High grade
- Poorly differentiated
- Highly irregular glands, difficult to discern, or
- Single cells and clusters
- Undifferentiated
Staging
- EGJ TNM is staged as esophagus
- Tumor center must be within 5 cm of and cross junction
- Intramucosal carcinoma is variably defined
and has poor interobserver agreement
- A strict definition requires at least focal identification of detached single infiltrating cell(s)
- A looser definition requires a cribriform pattern or growth in a pattern incompatible with pre-existing glands
- Marked crowding, branching, budding
- In either case, there is no invasion beyond the muscularis mucosae
