Fig. 2

Histological findings of the biopsy and breast conserving surgery. a Histopathological examination reveals proliferation of cancer cells with papillary structures, accounting for over 90 % of the whole lesion, supported by arborizing fibrovascular stroma (hematoxylin-eosin). b Pathological examination shows fibrosis and elastosis, which was thought to represent tissue replaced by cancer cells after neoadjuvant chemotherapy. However, no viable cancer cells were found and pCR was diagnosed