Parasternal Lymph Nodes Without the Muscles, Anterior View

Description

Along the parasternal line, a chain of parasternal (internal thoracic) lymph nodes tracks vertically on either side of the sternum, aligned with the internal thoracic vessels and the sternal ends of the costal cartilages. Ascending collecting lymphatic channels run superiorly parallel to the sternal borders, receiving tributaries from the anterior thoracic wall and the medial breast region before converging toward the root of the neck. Superiorly, the field extends into the anterior cervical region, where lymphatic trunks course deep to the clavicles toward the venous angles, with the mandible and upper cervical vertebrae providing bony orientation. No musculature obscures the planes, so the relationship of nodes to sternum, clavicles, and ribs reads cleanly. Parasternal nodes matter because they form a primary drainage pathway for the medial quadrants of the breast and for anterior intercostal spaces, a route that can bypass axillary basins and present as internal mammary chain involvement on sentinel lymph node mapping. This anterior, muscle-stripped rendering helps explain why radiotherapy fields and surgical planning sometimes target internal mammary nodes, and why cross-midline lymphatic communication can influence staging. A tight corridor. Easy to miss clinically. Use this asset in breast and thoracic oncology teaching (sentinel node concepts, internal mammary irradiation), in anatomy lab guides covering lymphatic drainage of the thoracic wall, or in surgical and radiology publications describing parasternal node assessment on ultrasound, CT, or PET-CT near the sternal margin. Anatomical accuracy verified by SciePro's Medical Advisory Board.