Large cisterna chyli, left renal stone and variant anomalous origins of both hepatic and left gastric arteries
Presentation
Left loin/flank pain. No past history of malignancy.
Patient Data
Images show:
- an oval-shaped radio-dense stone of about 2 x 1.5 cm size within the left renal pelvis associated with mild back pressure changes
- a well-defined, 4.1 x 3.5 x 2.2 cm, fluid-density, non-enhancing structure within the retro-crural region, that is seen passing through the aortic hiatus being posterior and to the right of the aorta consistent with a large cisterna chyli
- anomalous origins of the left gastric artery (from aorta), of left hepatic artery (from left gastric artery) and of right hepatic artery (from celiac artery).
An oval-shaped radio-dense stone of about 2 x 1.5 cm size within the left renal pelvis (red arrows) associated with mild back pressure changes. A well-defined, 4.1 x 3.5 x 2.2 cm, fluid-density, non-enhancing lesion in the retro-crural region (green arrows), that is seen passing through the aortic hiatus (blue arrows) being posterior and to the right of the aorta, consistent with a large cisterna chyli.
Case Discussion
The cisterna chyli is a normal anatomic structure seen as a dilated sac at the lower end of the thoracic duct. Multiple lymphatic channels (namely intestinal, two lumbar and paired descending inter-costal lymphatic trunks) open into this sac. It is located to the right of and slightly posterior to the aorta and anterior to the first and second lumbar vertebrae. About 100 mL of lymph is transported through the channel per hour.
The cisterna chyli is seen in 1.7% of patients evaluated with routine abdominal CT scans and in about 15% of patients evaluated with routine abdominal MR protocols that include highly fluid-sensitive T2-weighted imaging sequences.
Large cisterna chyli – described by some as giant – measures more than 2 cm in transverse diameter. Some of those were shown to exhibit delayed MR contrast enhancement 10 minutes after injection.
Large cisterna chyli may potentially be mistaken for enlarged retro-crural lymph node(s). Good points that help in identification of the cisterna chyli are:
- Characteristic location
- Tubular configuration
- Near-water attenuation value
- Almost no contrast enhancement
- Anatomical continuity with the thoracic duct, and
- Lack of substantial change in size despite changes in disease status at other sites (in case of following up a patient with adenopathy).