Adenocarcinoma of the Esophagus, Esophago-gastric Junction and Gastric Cardia
Grading / Staging
Grading
- WHO recommends well, moderately, poorly and undifferentiated
- No precise criteria given
- 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
- Well differentiated – well formed glands
- High grade
- Poorly differentiated
- Highly irregular glands, difficult to discern, or
- Single cells and clusters
- Undifferentiated
- Poorly differentiated
- Low grade
Staging
- EGJ TNM is the same as that used for esophagus
- 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
- Dense crowding, extensive branching and budding
- In either case, there is no invasion beyond the muscularis mucosae
- Duplication of muscularis mucosae can make staging difficult
- Common in Barrett esophagus (92% of cases)
- Not caused by the carcinoma
- Outer layer of duplication (or triplication) is generally continuous with the original layer
- Invasion between the duplicated layers is still considered T1 (intramucosal)
- Lewis 2008 reports 17% lymphatic invasion rate and 10% nodal metastases
- Higher than expected for T1
- Lower than expected for T2
- Estrella 2011 found no increase in nodal metastases
- Level of invasion should be described and thickness measured and given in report
- Recognition of this phenomenon can avoid over staging
- Duplicated muscularis mucosae is generally fragmented and not tightly bundled
- Normal muscularis propria is composed of well defined bundles of muscle
- Endoscopic biopsies and EMRs rarely contain muscularis propria
- Attention to edge of larger specimens can also be helpful
- True submucosa contains thick walled vessels and thick ropey collagen
- Stroma between muscularis mucosae layers contains thin walled vessels and fine collagen (in areas not involved by carcinoma)
- Collagen may become thicker in areas of desmoplasia
- Stroma between muscularis mucosae layers contains thin walled vessels and fine collagen (in areas not involved by carcinoma)
