Discussion
Diagnosis With Brief Discussion
- Diagnosis
- Bronchogenic cyst in retrocrural space
- Radiologic Findings
- Chest CT showed well-demarcated, encapsulated cystic lesion in left retrocrural space. The cystic mass showed homogenously low attenuation (28HU). This cystic lesion revealed isointense signal intensity, similar to CSF on T2WI and capsular enhancement on Gd-enhanced scan. On laparoscopic surgical intervention, this cystic mass contained yellowish, pus-like contents (below) and was closely attached to the psoas muscle. On pathologic examination, respiratory epithelium was aligned with the wall of cystic mass, which was consistent with bronchogenic cyst.
- Brief Review
- Bronchogenic cysts are congenital lesions thought to result from abnormal budding of the embryonic foregut. Mediastinal cysts are far more frequent and do not communicate with the bronchial tree, unlike intraparenchymal cysts in which such communications usually develop, leading to frequent recurrent infection.
At computed tomography (CT), bronchogenic cysts typically manifest as spherical masses of either water or soft-tissue attenuation. However, in one-half of all bronchogenic cysts, the CT density can vary from a low soft-tissue range to higher-than-muscle density, likely due to intracystic hemorrhage, protein, or calcium.
In one report, 68 histopathologically proven cases of bronchogenic cyst were analyzed. There were 58 mediastinal and 10 extramediastinal cysts (85% vs. 15%). Most common location of bronchogenic cyst is carinal area (52%), followed by paratracheal area (19%), esophageal wall (14%) and retrocardiacl area (9%). Especially, the extramediastinal cysts were located in the lung parenchyma (7/10), the diaphragm (2/10) and the pleura in one case. Rarely several cases in retroperitoneal bronchogenic cyst were reported.
On MR scan, bronchogenic cysts shows variable signal instensity which are slightly hyperintense or isointense to skeletal muscle on T1WI and isointense or hyperintense to CSF. These thin-walled cysts are lined with respiratory epithelium and cyst fluid is composed primarily of water admixed with varying amounts of thick proteinaceous mucus. Calcium oxalate crystals have also been detected in the fluid.
Mediastinal cysts are far more frequent and do not communicate with the bronchial tree, unlike intraparenchymal cysts in which such communications usually develop, leading to frequent recurrent infection.
- References
- 1. McAdams HP, Kirejczyk WM, Rosado-de-Christenson ML, Matsumoto S. Bronchogenic cyst: imaging features with clinical and histopathologic correlation. Radiology 2000; 217(2):441-6.
2. Nakata H, Nakayama C, Kimoto T, et al. Computed tomography of mediastinal bronchogenic cysts. J Comput Assist Tomogr 1982; 6:733-738
3. Glazer JS, Siegel MJ, Sagel SS. Low-attenuation mediastinal masses on CT. AJR 1989;152:1173-1177
- Keywords
- mediastinum, retrocrural space, congenital,