Interpectoral Lymphatics (Mammary Gland)

Description

Anterior thoracic wall anatomy is sectioned to expose the mammary gland with its lobules embedded in adipose tissue and tethered by fibrous septa (suspensory ligaments) extending toward the dermis and nipple-areolar complex. Fine lymphatic vessels course through the glandular parenchyma and converge toward the interpectoral (Rotter) lymph nodes positioned between pectoralis major anteriorly and pectoralis minor posteriorly, along the pectoral fascia. Deep to the breast, the pectoralis major fibers provide a clear posterior boundary and a surgical plane for following lymphatic drainage. Interpectoral lymphatics matter because they form a clinically relevant bridge between superficial breast lymph drainage and the axillary nodal basin, and they can harbor metastatic disease even when more obvious axillary nodes are not enlarged. During breast-conserving surgery or mastectomy, Rotter nodes may be encountered when dissecting the pectoral fascia or developing the interpectoral space, and their involvement can affect pathologic staging and radiotherapy fields. A small structure. A frequent source of under-sampling when the dissection stays too superficial. Use this artwork to teach breast lymphatic pathways in gross anatomy and surgical anatomy courses, to illustrate sentinel lymph node mapping discussions in breast oncology modules, or to support atlas figures and review articles describing axillary level anatomy and regional nodal staging. It also works well in patient-education materials explaining why deeper nodes between the pectoral muscles may be assessed despite an otherwise localized lesion. Anatomical accuracy verified by SciePro's Medical Advisory Board.