Topographical analysis of lymphatic pathways from the meso- and hypopharynx based on minute cadaveric dissections: possible application to neck dissection in pharyngeal cancer surgery.

Abstract

To facilitate the development of new operative procedures for pharyngeal cancer, it is important to understand the precise location of the lymph nodes and their pathways. Minute dissection of 22 neck-halves (11 adult cadavers) was undertaken to determine the location and topographical relationships of the lymphatics of the pharynx. Four groups of lymph nodes on the drainage pathways from the meso- and hypopharynx to the internal jugular nodes were classified according to their topographical relationships to the carotid arteries: lateral pharyngeal, superior thyroid, lateral retropharyngeal and medial retropharyngeal nodes. Lymphatics from the mesopharynx passed laterally to lateral pharyngeal or jugulodigastric nodes or slightly upward to lateral retropharyngeal nodes. Lymphatic drainage from the hypopharynx was multidirectional with the pathways being classified as follows: ascending pathway to the lateral pharyngeal and lateral retropharyngeal nodes, lateral pathway to the internal jugular chain, and descending pathway connecting to the uppermost vessels ascending from the recurrent laryngeal nerve chain. In addition, a contralateral pathway was found originating from the hypopharynx extending to the contralateral internal jugular chain. These findings provide valuable information for comparison with CT and MRI studies, as well as with clinicopathological data, to clarify the precise mode of metastasis in head and neck cancers. These results are also applicable to neck dissection in meso- and hypopharyngeal cancers.