Intercostal Muscles Related to the Breast

Description

Cut in sagittal section, the mamma is shown with skin and subcutaneous adipose tissue superficial to the mammary gland, where lactiferous ducts converge toward the papilla mammae and are supported by fibrous septa consistent with the suspensory (Cooper) ligaments. Deep to the gland, the retromammary space separates breast tissue from the fascia over pectoralis major, and posterior to that plane the thoracic wall comes into view. External intercostal and internal intercostal muscles occupy the intercostal spaces between adjacent ribs, layered superficial to the endothoracic fascia and pleura, and positioned inferior and posterior to the bulk of the pectoralis major in this section. A sagittal cut like this clarifies what sits where during breast examination and surgery: parenchyma and ducts remain superficial to pectoralis fascia, while pain or fixation arising from chest wall invasion tracks deeper toward the intercostal muscles and ribs. That relationship becomes concrete when planning mastectomy dissection planes, interpreting tumor adherence to pectoralis fascia, or understanding why posterior breast lesions can refer pain along intercostal nerves running with the intercostal vessels in the costal groove. Depth matters. Use this artwork in gross anatomy and breast imaging teaching to orient learners to the retromammary plane, the pectoral fascia as a surgical landmark, and the thoracic wall layers that underlie the breast. It also fits surgical oncology, plastic and reconstructive surgery, and radiology publications illustrating chest wall involvement, flap planning, or postoperative anatomy after mastectomy. Anatomical accuracy verified by SciePro's Medical Advisory Board.