Morphological and immunohistochemical characterization of the mammary gland in postmenopausal women

Abstract

Background A comprehensive understanding of the histological and immunological landscape of the normal aging breast is crucial for establishing a baseline to differentiate physiological from pathological changes. This study aimed to perform a detailed characterization of the morphological features and immune cell landscape in normal postmenopausal breast tissue, providing foundational data for comparative pathology. Material and methods The study was conducted on 30 normal breast tissue samples obtained from women aged 50 to 86, who died of accidental causes. The analysis involved standard histopathology (HE) and a comprehensive immunohistochemical panel for estrogen receptor (ER), progesterone receptor (PR), immune and immune – angiogenic markers (CD3, CD4, CD8, CD34, CD45, CD56, CD68). Results Histological examination revealed characteristic age-related changes, including periductal fibrosis (50%), glandular involution (36.7%) and increased stromal connective tissue (46.7%). Immunohistochemistry revealed a distinct topographical distribution of immune cells, with T helper (CD4+) and NK (CD56+) cells predominantly localized in the epithelial compartment, while CD3+ and CD8+ T lymphocytes were more evenly distributed. Angiogenesis (CD34+) was observed exclusively in the periductal stroma. ER and PR were expressed in luminal epithelial cells. Conclusions The postmenopausal breast gland undergoes significant morphological and immunological remodeling. This study offers a comprehensive quantitative and qualitative characterization of the normal tissue microenvironment, essential for the correct interpretation of pathological findings in breast diseases during aging.