A case of thoracic esophageal cancer with an unusual type of duplicated inferior vena cava.

We describe here a thoracic esophageal cancer with an unusual type of duplicated inferior vena cava. A 58-year-old man was referred to our hospital because a tumor in his lower esophagus had been identified by endoscopy and radiology. Computed tomography scans showed an unusual type of duplicated inferior vena cava characterized by both common iliac veins flowing back into the left-sided inferior vena cava, which drained into the azygos vein, whereas the right-sided one had no drainage. Esophagectomy was performed 3 weeks later after preoperative chemotherapy. Because the patient could have developed thrombosis of the left-sided inferior vena cava and severe hypotension caused by decreased venous return to the heart if the azygos vein had been severed, the azygos vein was preserved. Thus, when performing surgery for thoracic esophageal cancer, the surgeon should check for a duplicated inferior vena cava and preserve the azygos vein if necessary.