Left-Sided Cisterna Chyli: a Case Report on a Rare Normal Anatomic Structure

The cisterna chyli, a dilated lymphatic sac in the retrocrural space, is usually located to the right of the aorta. We report a case of a left-sided cisterna chyli, which was incidentally detected on the radiologic examinations of a preoperative workup for cholangiocarcinoma. Computed tomography (CT) and magnetic resonance (MR) images revealed a cisterna chyli measuring 2.5 cm in length in the left retrocrural space. The dilated lumbar lymphatics joined with the cisterna chyli, which was continuous with the left-sided thoracic duct. To the best of our knowledge, this is the second antemortem case of a left-sided cisterna chyli in literature. The cisterna chyli can mimic retrocrural lymphadenopathy, solid tumor with cystic degeneration, abscess or hematoma. The left-sided cisterna chyli should be referred to as a structure so as to be cautious in surgical approach.