LYMPHATIC DRAINAGE OF THE SKULL BASE: COMPARATIVE ANATOMIC AND ADVANCED IMAGING STUDIES IN THE RABBIT AND HUMAN WITH IMPLICATIONS FOR SPREAD OF NASOPHARYNGEAL CARCINOMA

Abstract

This preliminary study investigated thelymphatic drainage and distribution oflymphatic structures in the skull base.Characteristics of the rabbit skull base wereanalyzed and compared correspondingly withthose of the human skull. The lymphaticcirculation in the rabbit cranial base wasdetected by digital subtraction angiography(DSA), and lymph drainage in the humanskull base was illustrated by interstitialmagnetic resonance lymphography (MRL).Lymphatic structures and their distributionin MRL were identified by comparing withcontrast-enhanced MRI and clinical data onbasilar metastasis of nasopharyngealcarcinoma (NPC) in the human skull base.Anatomic similarity was found between therabbit and human basilar regions. Wellvisualizedlymphatic pathways were found inthe rabbit cranial base, and human lymphaticstructures showed high signal intensity inenhanced T1-weighted MRL images. Lymphatictissues in the human basilar region werefound mainly distributed in the areas of thejugular foramen, foramen lacerum, andpetrosal section of the internal carotid artery(ICA). Their distribution in the human basilarregion was similar to the distribution in therabbit basilar region and consistent with ourclinical findings of the predilection sites ofNPC metastasis in the skull base. Our studiesshow that bilateral symmetrical lymphaticstructures were distributed along the ICA,internal jugular vein, and dura of cranial basein the central part of the middle and posteriorskull base.