Histologic Type (Note D) ___ No residual invasive carcinoma ___ Invasive carcinoma of no special type (invasive ductal carcinoma, not otherwise specified) ___ Micro-invasive carcinoma ___ Invasive lobular carcinoma ___ Invasive carcinoma with lobular features ___ Invasive carcinoma with ductal and lobular features (“mixed type carcinoma”)
Invasive lobular carcinoma (ILC) is the second most common subtype of breast carcinoma following invasive breast carcinoma of no special type (NST), accounting for 10–15% of breast carcinoma . It has unique clinical, imaging, histological, immunohistochemical, and molecular features.
Fifteen patients were affected with ductal carcinoma in situ, 122 by invasive carcinoma of no special type, and 19 with invasive lobular carcinoma. Out of a total of 141 invasive cancers, 45 were luminal A-like, 54 luminal B-like, 5 human epidermal growth factor receptor 2 (HER2) positive, and 37 triple negative.
Invasive lobular carcinoma is the most common special breast carcinoma subtype, with unique morphological (discohesive cells, single-cell files, targetoid pattern) and immunohistochemical (loss of E-cadherin and β-catenin staining) features. Moreover, ILC displays a poor response to neoadjuvant therapy, a different metastatic pattern compared to invasive breast carcinoma of no special type
The most common histologic type of invasive breast cancer is now classified as invasive breast carcinoma of no special type (IBC-NST), changed in the fourth edition of the World Health Organization (WHO) Classification of tumors of the breast from invasive ductal carcinoma not otherwise specified (IDC-NOS). 1 The term “ductal” is no longer
. 117 138 60 495 454 210 458 203
invasive carcinoma of no special type
