Table 1 Summary of different WHO classifications.
From: Breast cancer with neuroendocrine differentiation: an update based on the latest WHO classification
WHO | Terminology | Definition | Subtypes | NE marker profile |
|---|---|---|---|---|
2003 | Neuroendocrine tumor | • Morphological features similar to those of NE tumors of both GI tract and lung • Express NE marker of 50% of cell population • IBC-NOS with focal NED revealed by NE markers in scattered cells were excluded. | • Solid neuroendocrine carcinoma • Small cell/oat cell carcinoma • Large cell carcinoma | • CG and/or SYN • NSE described in poorly-differentiated/small cell carcinoma |
2012 | Carcinoma with neuroendocrine features | • Morphological features similar to those of NE tumors of GI tract and lung • Express NE marker to a greater or a lesser degree • IBC-NST and special subtypes with NED were included. | • Neuroendocrine tumor, well differentiated • Neuroendocrine tumor, poorly-differentiated/small cell carcinoma • IBC with neuroendocrine differentiation (included mucinous carcinoma and solid papillary carcinoma with NED) | • CG and/or SYN • NSE described in poorly-differentiated/small cell carcinoma |
2019 | Neuroendocrine neoplasm | • Tumor with predominant (>90%) NED • Solid papillary carcinoma and hypercellular subtype of mucinous carcinoma were excluded | • NET • NEC (small cell NEC; large cell NEC) | • CG and/or SYN expression is characteristic in NET, Some also express CD56 • CG and/or SYN in 2/3 of NEC and expression of PGP9.5, CD56 and NSE in majority of NEC |
Invasive breast cancer NST with neuroendocrine features | • ≤90% NE histological features or NE marker expression ➢ 10–90%: mixed invasive NST and NET/NEC ➢ <10%: invasive NST commented on the focal NE pattern |
