Age / Sex : 61 / F

Chief complaint: Cystic lesion, incidentally discovered on MRI of lumbar spines

What is your impression?

Two weeks later, you can see the final diagnosis with a brief discussion of this case.

(답안은 한 개만 보내주시기 바랍니다)

Courtesy: 정준용 (Joon Yong Jung), 가톨릭대학교 서울성모병원 (Seoul St. Mary’s hospital, The Catholic University of Korea)

Cisterna chyli

Discussion

Findings:

There is a cystic structure which just lies on the anterior aspect of the intervertebral disk of L1-2. Thin tubular structures are arising from the cyst at its cranial and caudal aspects.

Differential Diagnosis:

 Lymphadenopathy

Anterior herniated disk with cystic degeneration

Diagnosis: Cisterna chyli

Discussion:

Cisterna chyli is the initial prominent segment of the thoracic duct. Anatomically, it is joined by two lumbar and intestinal lymphatic trunks and then it continues in the cephalic direction as the thoracic duct. It is typically located in the retrocrural space at the level of T12-L2 vertebral column (1,2). In a study, the cisterna chyli appeared in 30% of patients who received routine abdominal MR (2).

The cisterna chyli appears as a variably shaped fluid-filled structure in the retrocrural space. On CT images, the cisterna chili may be mistaken for a retrocrural lymph node. However, the depiction of fluid content of the cisterna chili on MR images permits its accurate identification. It has minimal or no enhancement within 5 minutes, but intensely enhanced on delayed phase (3).

References:

1.     Erden A. Cisterna chyli: an incidental finding on MR cholangiopancreatography. AJR 2004;182:262

2.     Pinto PS. Sirlin CB, Andrade-Barreto, OA. et al. Cisterna chyli at routine abdominal MR imaging: a normal anatomic structure in the retrocrural space. Radiographics 2004;24:809-817

3.     Verma SK, Mitchell DG, Bergin D. et al. The cisterna chyli: enhancement on delayed phase MR images after intravenous administration of gadolinium chelate. Radiology 2007;244:791-796