Table 2.
Differential diagnosis of terminal end bud (TEB), intraductal proliferation (IDP), and carcinoma in situ (CIS)
| Tissue Components | TEB | IDP | CIS |
|---|---|---|---|
| Basement membrane | Present | Present | Present |
| Periductal stroma | Normal | Moderate desmoplastic reaction | Marked desmoplastic reaction |
| Inflammatory reaction | Absent | Moderate | Marked |
| Luminal border | Smooth | Serrated | Irregular |
| Secondary luminal | Absent | Absent | Present in cribriform pattern |
| Micropapillae | Absent | Some | May be prominent |
| Epithelium | Heterogeneous three cell types | Predominance of one cell type | Predominance of one cell type |
| Mitoses | Numerous | Numerous | Numerous |