Postmortem Evidence of Lymphatic Vessels Located at the Boundary of Central and Peripheral Nervous Systems in the Cervical Spine.

Abstract

Recent modern characterizations of human meningeal lymphatic vessels have reframed long-standing views of central nervous system neurofluid drainage. However, gross anatomical data on lymphatic vessels remains sparse. In this cadaveric study, we combined dissections and immunohistochemical analysis in formalin-fixed human body donors to characterize lymphatic vessels associated with cervical spinal nerves. Using manual, low-pressure peroxide-dye injections via the thoracic duct and left jugular lymphatic trunk, we effervesced and identified candidate lymphatic pathways extending toward the head and neck, highlighting vessels accompanying cervical spinal nerves at the interface between the vertebral canal and surrounding soft tissues. Dye-identified vessels and adjacent dural and perineural tissues were harvested and processed for D2-40 immunohistochemistry, targeting the lymphatic endothelial marker podoplanin. Across four of nine donors, we observed D2-40-positive, thin-walled luminal structures within epineurial and peridural compartments at the craniovertebral junction, along cervical intervertebral foramina, and near brachial plexus roots, consistent with lymphatic vessels. These findings identify D2-40-positive vessel profiles consistent with lymphatic vasculature extending along spinal nerves without directly demonstrating intradural channels or cerebrospinal fluid outflow. They provide an anatomical framework for future studies probing how cervical lymphatic networks at CNS interfaces contribute to neurofluid drainage, immune cell trafficking, and neurological disease.