A detailed pathway and termination of thoracic duct in a Japanese female cadaver with situs inversus totalis

Although the thoracic duct (TD) requires special attention during thoracic surgery, to our knowledge, its detailed course in the situs inversus totalis (SIT) case has not been reported. We encountered an 86-year-old Japanese female cadaver with SIT during a student anatomical practice and examine the TD. The TD originated from the cisterna chyli at the level of the 2nd lumbar vertebra, ascended along with the left side of aorta and then passed behind the aortic arch on the right side of the esophagus. The TD turned right at the first thoracic vertebra and finally emptied into the basal portion of the right external jugular vein without branching. The present running pathway of the TD was approximately in the inverted position of the normal, but its connection site to the vein and manner was very rare and has not been reported to date. Therefore, this junctional anomaly may occur during the developmental period in SIT. Further anatomical and embryological studies are required, but this report provides useful morphogenetic information of the TD and lymphovenous junction in SIT.