대한흉부영상의학회 Korean Society of Thoracic Radiology

Discussion

Diagnosis With Brief Discussion

Diagnosis

Esophageal duplication cyst

Radiologic Findings

Chest radiograph shows a right paravertebral bulging mass at T4 level.
Nonenhanced CT scan demonstrates a homogeneous, smoothly marginated, right posterior mediastinal mass (mean attenuation: 60 HU) abutting the trachea and esophagus.
On contrast enhanced CT scan, the mass does not show contrast enhancement (mean attenuation: 55 HU).

Brief Review

Esophageal duplication cysts are uncommon and constitute only 0.5 - 2.5 % of all esophageal tumors (1,2). Of duplication cysts, 60% are located in the lower esophagus.
The rest are distributed equally between the upper and middle thirds of the esophagus (2).
Duplication cysts of congenital origin may be attached to the esophagus in a paraesophageal location or may be intramural.
Attached cysts often protruded into the posterior mediastinum and may up to 5 cm in diameter (3).
Esophageal duplication cysts probably result from developmental errors occurring at the fifth to eight week of life (2). Embryologically, esophageal duplication cysts are believed to represent a failure of complete vacuolation of the originally solid esophagus to produce a hollow tube.
They are lined by nonkeratinizing squamous or ciliated columnar epithelium: a double layer of smooth muscle in their walls and absence of cartilage are necessary findings to exclude a diagnosis of bronchial cyst (4).

Radiologic findings using multiple methods are often non-specific.
Chest radiographs may show a middle or posterior mediastinal mass.
Barium swallow examination may demonstrate a smooth, rounded impression on the esophagus.
Radionuclide scans using Tc99m sodium pertechnetate may be helpful in children, in whom 50% of thoracic duplication cysts contain ectopic gastric mucosa (5).

Typical CT finding of esophageal duplication cyst is a homogeneous, low-attenuation mass with smooth borders (6).
Although CT cannot definitely differentiate an esophageal duplication cyst from other benign paraesophageal lesions such as abscess, old hematoma, neurofibroma, lipoma, leiomyoma, or other foregut duplications, it can often suggest a presumptive diagnosis (7).

The differential point with bronchogenic cyst is that the wall of the lesion may be thicker and the mass may assume a more tubular shape with more intimate contact with the esophagus(8).

References

1. Bower RJ, Kieswetter WB. Mediastinal masses in infants and children. Arch Surg 1977; 112: 1003-1009.
2. Whitaker JA, Deffenbaugh LD, Cooke AR. Esophageal duplication cyst. Am J Gastroenterol 1980; 73: 329-332.
3. Spjut HJ. Pathology. Dodds WJ. Radiology. In: Margulis AR, Burhenne HJ, eds. Alimentary tract radiology. St. Louis; Mosby, 1983: 521-528, 529-603.
4. Fraser RS, Pare JA, Fraser RG, Pare PD. Synopsis of diseases of the chest, second edition. Philadelphia; Saunders, 1994: 936.
5. Feguson CC, Young LN, Sutherland JB, Macpherson RI. Intrathoracic gastrogenic cyst-preoperative diagnosis by technetium scan. J Pediatr Surg 1973; 8: 827-828.
6. Weiss L, Fragelman D, Warhit JM. CT demonstration of an esophageal duplication cyst. J Comput Assist Tomogr 1983; 7: 716-718.
7. Kuhlman JE, Fishman EK, Wang KP, Siegelman SS. Esophageal duplication cyst: CT and transesophageal needle aspiration. Am J Roentgenol 1985; 145: 531-532.
8. Amstrong P, Wilson AG, Dee P, Hansell DM. Imaging of diseases of the chest, second edition. St. Louis; Mosby, 1995: 736.

Keywords

Esophagus, Mediastinum, Congenital,