Lobular involution primarily involves the replacement of which tissue type with fatty tissue?

Lobular involution refers to the process where the lobules in the breast undergo changes that lead to a reduction in glandular tissue. This process is characterized by the replacement of glandular elements—such as secretory cells and ducts—along with the surrounding stroma (the supportive connective tissue) with fatty tissue. As a woman ages, especially after menopause, the breast experiences a significant transformation where active glandular tissue diminishes, and fatty tissue becomes more prevalent.

This shift is important as it represents a normal physiological change rather than a pathological one, reflecting the natural life cycle of breast tissue that adapts over time. Fatty tissue provides insulation and affects the overall structure and shape of the breast, contributing to a softer feel. Understanding this process is crucial for health professionals, especially in the context of mammography interpretation and recognizing normal versus abnormal changes in breast tissue.