Table 3 Differential diagnosis criteria between invasive large duct type adenocarcinoma and non-invasive tumors
Large duct type adenocarcinoma | Mucinous cystic neoplasm | Intraductal papillary mucinous neoplasm | Pancreatic intraepithelial; neoplasm (PanIN) | |
|---|---|---|---|---|
Ducts | ||||
Contours | Jagged, irregular | Smooth, round | Smooth, round | Smooth, undulating |
Distribution | Irregular, focally clustered, but separated by stroma | Regular, closely packed | Regular, separated by pancreatic tissue or fibrosis | Regular |
Tributary ducts | Absent | May have attached daughter microcysts | Present | Present |
Contents | Intraluminal mucin, neutrophils and necrotic debris | Minimal mucin precipitation | Clear in low-grade PanIN | |
May be necrotic in high-grade PanIN | ||||
Cysts | May be microcystic | Megacystic | Microcystic or megacystic | Microcystic |
Papillae | When present, they are microscopic | Grossly visible papillary nodules in some cases | Grossly visible papillary nodules in many cases | Mucosal folds |
Rare abortive short papillae | ||||
Stroma | ||||
Myxoid/desmoplastic | Present | Absent | Absent | Absent |
Cellular | Occasional desmoplastic type | Ovarian-like | Absent | Absent |
Desmin (−) | Desmin + | |||
Actin ++ | Actin ++ | |||
ER/PR (−) | ER/PR + | |||
Neural invasion | May be present | Absent | Absent | Absent |
