1Case Report
A 17-year-old teenager presented with upper abdominal pain for half a year. The symptoms become more severe in the last 3 months. Physical examination was normal and the results of blood tests were within normal range. Endoscopic examination of the upper gastrointestinal tract (EGD) showed congested and edematous mucosa of the gastric antrum and subepithelial bulging was seen on the posterior wall of the gastric antrum with spherical shape and smooth surface [Figure 1] (1, 2).
Transcutaneous ultrasound was performed with a S60 equipment (SonoScape, Shenzhen, China; C1-6A convex array probe, 12L-A linear array probe). Examination of the stomach reveals an anechoic cystic mass of about 19 × 12 mm in the gastric antrum cavity with regular margins and morphology. The wall thickness was about 2.3 mm. Real time ultrasound scanning revealed that the mass moved with the peristalsis of the stomach [Figure 2].
High-frequency ultrasound scan was performed using a linear transducer to observe the relationship of the mass to the gastric wall. The layer of the cyst was connected with the muscular layer of the gastric wall showing a double-wall sign with hyperechoic submucosal and hypoechoic muscular layer. The use of sepia tint map of B mode ultrasound might even show more clearly the defined layers of the cyst [Figure 3].
Then, double contrast enhanced ultrasound (CEUS) was performed. CEUS via intravenous injection of SonoVue 2.4 mL (Bracco SpA, Milan, Italy) as contrast agent. The degree of the cystic wall enhancement was similar to that of the gastric wall. The patient was instructed to take 100 ml of tap water with 5 drops of SonoVue contrast agent orally to observe if the cystic part of the mass was connected to the gastric cavity. It was found that the contrast agents did not enter the mass demonstrating that the mass was not connected to the gastric cavity [Figure 4].
Contrast enhanced computed tomography (CECT) of the abdomen was performed, which revealed a non-enhanced cystic lesion of size 11 x 18 mm in curvature of the gastric antrum. The cyst showed no internal septations and calcifications. The enhancement degree of cystic wall was similar to that of the gastric wall [Figure 5].
Based on the clinical symptoms and the former two cross-sectional imaging methods, the clinical diagnosis was a gastric duplication cyst non-communicating with the gastrointestinal tract. Surgical resection is considered to be a curative treatment in symptomatic patients.
2Discussion
Gastrointestinal duplication cysts (GDCs) are rare congenital anomalies that primarily occur in childhood, accounting for about 4 % of all intestinal duplications (4). We report a 17-year-old teenager who was admitted to our hospital for the upper abdomen pain. Symptoms of GDCs usually present with upper abdominal pain, vomiting, and occasionally as palpable abdominal masses (5). Diagnostic imaging, especially cross-sectional techniques, plays a crucial role in recognizing these cysts. Among these, double contrast enhanced ultrasound (CEUS) combines oral contrast enhanced ultrasound with intravenous microbubbles may provide important diagnostic information. It is a noninvasive, radiation-free and reliable approach, as an innovative modality to screen the diseases of gastrointestinal tract such as gastric tumors (6).
Double contrast enhanced ultrasound (CEUS) revealed a cystic mass in the antrum of the stomach. In this case, the initial clinical symptoms were non-specific, patient admitted for subepithelial bulge suggested by EGD. Although both CECT and CEUS suggest GDC, CEUS provides more imaging information for clinical including the layer of the cystic wall. Also, CEUS showed its relationship to the gastric wall and to the gastric lumen. Diagnostic and interventional endoscopic ultrasound is often used in suspected subepithelial lesions (7) but was not performed in this patient.
The essential features for GDC diagnosis include: 1) the cyst wall is continuous with the stomach; 2) the smooth muscle layer of the cyst is shared with the stomach; 3) the cyst is lined with gastrointestinal epithelium; 4) the cyst and the stomach share a common blood supply (8, 9).
Duplication cysts can be cystic or tubular and may be communicating or non-communicating with the gastrointestinal tract. The most common type (80 %) is the cystic and non-communicating form (10).
3Conclusion
This patient presented a cystic and non-communicating duplication cyst diagnosed by CEUS. Double contrast enhanced ultrasound as a real-time dynamic, noninvasive, radiation-free and reliable imaging method, could provide important imaging details for diagnosing gastric duplication cysts in individual patients.
4Key words
gastrointestinal duplication cyst; diagnosis; double contrast enhanced ultrasound (CEUS)
5References
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