Table 2. Immunohistochemical markers for the differential diagnosis of in situ-mimicking architectures in metastasis to the breast
| Â | Extramammary organ/tumor-specific | Breast-related | Myoepithelial | Lymphatic endothelial |
|---|---|---|---|---|
Lymphovascular tumor emboli | (+) | (−) | (−) | (+) |
Intraductal spread by metastatic tumorsa | (+) | (−) | (+) | (−) |
Coexistence of true in situ carcinoma | (−) | (+) | (+) | (−) |