Introduction The word apocrine in medical literature is used in general to denote a gland or cell exhibiting a distinct type of glandular secretion in which the free end of the secreting cell is cast off along with the secretory…
Metaplastic breast carcinomas are a heterogeneous group that can display adenocarcinoma, squamous, spindle cell, and/or heterologous mesenchymal growth patterns, often in various combinations. These combinations have suggested monikers such as matrix-producing carcinoma , carcinosarcoma , spindle cell carcinoma , and…
Introduction Triple-negative breast cancer (TNBC) lacks expression of the estrogen receptor (ER), progesterone receptor (PgR), and human epidermal growth factor 2 (HER2) and accounts for approximately 15% of invasive breast cancers (IBCs) among screened individuals and up to 20% to…
IDC, or ductal carcinoma of no special type (ductal NST), is a heterogeneous group of tumors that fail to exhibit sufficient characteristics to achieve classification as a specific histological type, such as lobular, mucinous, or tubular carcinoma ( Fig. 23.1…
Ductal carcinoma in situ (DCIS) is a heterogeneous group of lesions defined as a proliferation of neoplastic epithelial cells within the mammary duct lobular system. Major diagnostic criteria that differentiate DCIS from invasive cancer are the presence of intact basement…
Despite the earlier descriptions by Ewing, the term lobular carcinoma is largely credited to Foote and Stewart, who, in 1941, published their seminal paper describing a detailed morphological analysis of a distinctive subgroup of in situ carcinomas of the breast,…
Introduction Historically, breast cancers have been classified broadly based on morphology into ductal and lobular types and characterized by tumor grading. A smaller percentage of tumors are classified as “special subtype carcinomas.” This classification system has provided useful prognostic information.…
Introduction: Screening and Detection As the imaging modalities used for breast cancer screening and diagnosis have improved, the types of specimens evaluated by pathologists for risk-associated lesions have changed. In contemporary practice, atypical ductal hyperplasia (ADH) and atypical lobular hyperplasia…
Fibrocystic change (FCC) refers to a complex of lesions including gross and/or microscopic cysts, apocrine metaplasia, fibrosis, and blunt duct adenosis (BDA), and minor degrees of sclerosing adenosis and usual epithelial hyperplasia. It is important to realize that cystic change…
The epithelial system of the breast consists of a ductal system and terminal ductal lobular units, both of which are lined by two cell layers: an inner layer of luminal epithelial cells facing the lumen and an outer layer of…