Functional anatomy of the lymphatic drainage system of the upper aerodigestive tract and its role in metastasis of squamous cell carcinoma

Background. Although there is a significant understanding of the vascular anatomy of the upper aerodigestive tract (UADT), there is less detailed knowledge of the architecture and drainage patterns of the lymphatic system. Detailed knowledge of the lymphatic system is critical for understanding the role of sentinal node identification in the management of different cancers. Methods. We have combined microscopic techniques with in vivo and in vitro lymphographic studies to survey the architecture and drainage patterns of the lymphatic system of the UADT in 850 organ specimens. Results. These studies show an interaction of superficial and deep lymphatic networks that vary in density but have a constant distribution characterized by predictable patterns of lymph drainage into the regional lymph nodes. Conclusions. Detailed knowledge of the lymphatic system of the UADT contributes to a better understanding of the patterns of metastatic spread of carcinomas of the UADT and provides a strong rationale for the practice of sentinel node identification in the management of these tumors.