Table 1 Differential diagnosis of Invasive carcinoma with apocrine differentiation
From: Apocrine lesions of breast and invasive carcinoma with apocrine differentiation: a brief review
Tumor type | Histology | IHC |
|---|---|---|
Invasive breast carcinoma of no special type | No apocrine morphology / Apocrine morphology less than 90% | ER +/-, AR +/- |
Carcinoma with apocrine differentiation | Apocrine morphology in more than 90% of tumor | ER / PR -, AR +, Her2neu +/- |
Granular cell tumor: | Large, round to polygonal tumor cells with pink granular cytoplasm and central small nuclei | Positive for S100 and CD68; negative for CKs |
Apocrine DCIS | DCIS with apocrine cytology, Myoepithelial cells intact | ER -, AR + |
Apocrine adenosis / atypical apocrine adenosis | Preserved lobular architecture, proliferation with apocrine morphology, stromal fibrosis / sclerosis, Myoepithelial layer intact | Not needed |
Histiocytic proliferations | Pale to foamy cytoplasm without nuclear atypia | CD68 + |