Gastric duplication cyst

A gastric duplication cyst is a rare congenital anomalyforegut duplication cyst affecting the stomach. It accounts for less than 10% of all gastrointestinal duplications (see enteric duplication cysts). The most common site of gastrointestinal tract duplication cysts (GTDC's) are the ileum,followed by oesophagus, large bowel and jejunum.

Epidemiology

A review of four large series comprising 281 cases of GTD¹, demonstrated that duplications of the stomach constituted about 7%. 

Clinical presentation

Clinical manifestations are dependent on location, size, and mucosal pattern. Symptoms usually appear before one year of age as an upper abdominal obstruction,abdominal pain or a palpable mass ².

Pathology

By definition, the gastric duplication have some defining characteristics as a well developed layer of smooth muscle, an epithelial lining represents some part of the alimentary tract, and are attached to some part of the stomach sharing a common muscle wall and blood supply ³

Duplication cysts may also contain heterotopic tissue which can include

• gastric mucosa
• pancreas: ectopic pancreatic tissue
• lymphoid tissue
• respiratory epithelium 

Location

The majority are non-communicating, spherical cysts and the greater curve is the most common site of its occurence ¹.

Radiographic features

Plain film: abdominal radiograph

Abdominal plain radiography can demonstrate a soft tissue mass displacing air-filled bowel loops. There can be occasional calcification in the cysts wall ⁶.

Ultrasound

Sonography plays an important role in these patients and many authors have demonstrated that the combination of an echogenic inner mucosal layer and hypoechoic outer muscular layer are highly suggestive of a GTDC ⁴.

Fluoroscopy

A Barium study may show filling defect due an extrinsic compression from these cystic masses

CT

CT scans will show a fluid-attenuation cystic mass in close contact with the stomach. 

MRI

Magnetic resonance demonstrates features common to cysts with typical signal characteristics being

• T1: low signal         
• T2: high signal
• T1 C+ (Gd): the cyst wall can show slight enhancement ⁶

Complications

Recognised complications include:

• gastrointestinal tract bleeding
• gastric perforation 
• torsion ⁸

The above complications are especially likely if duplications cysts contain ectopic gastric mucosa (which occurs in 20-50% of duplications) or ectopic pancreatic tissue ⁶.

Differential diagnosis

General imaging differential considerations include

• pancreatic pseudocyst
• other enteric duplication cysts
• it can sometimes be challenging to differentiate from a cystic adrenal lesion on the left (especially if large with little intervening tissue)