A Rare Lymphatico-Venous Communication Associated with Duplication of Thoracic Duct Una rara Comunicación Linfático-venosa Asociada con Duplicación del Conducto Torácico

SUMMARY: An unusual presentation of the duplication of thoracic duct with a rare lymphatico- venous communication wasfound during the routine dissection for undergraduate students. The thoracic duct duplicated at the level of T12 vertebra. Normallythoracic duct opens into the junction of left internal jugular vein and subclavian vein. On the right side of the neck, the right lymphaticduct conveys the lymph from the head and neck, the upper extremity and the right side of the thorax to the right innominate vein. Here,the duplicated thoracic duct on the left side opened directly into the inferior vena cava. The above case is discussed with regard to itsdevelopment, incidence, and clinical significance. KEY WORDS: Thoracic duct; Inferior vena cava; Lymphatico-venous communications; Cisterna chyli; Lymphatic duct. INTRODUCTION The lymphatic system is a network of channels thatare found in all tissues in organs throughout the body. Thesechannels, except for the lacteals which contain a milkyfluid called chyle, contain a clear liquid known as lymphwhich drains to the lymph nodes and ultimately reachesthe thoracic duct or the right lymphatic duct which directthe lymph into the venous system at the junction of thejugular and subclavian veins on either side (Leeds, 1997).The thoracic duct begins from the upper end of cis-terna chyli at the lower border of T12 vertebra and entersthe thorax usually through the aortic opening of thediaphragm (Dutta, 2000). It passes upwards in the poste-rior mediastinum behind the oesaphagus. Opposite T5vertebra the thoracic duct inclines to the left and then runsupwards in the superior mediastinum, along the left edgeof the oesaphagus. At the root of the neck, it arches laterallyopposite the transverse process of C7 vertebra and finallyturns downwards to terminate in the angle formed by thejunction of the left internal jugular vein and the leftsubclavian vein (Dutta).