Supplementary Material for: Delayed Presenting Gastric Duplication Cyst Mimicking a Left Adrenal Cyst in a Young Female: A Case Report with a Literature Review

Gastric duplication cyst (GDC) is a rare congenital anomaly of the gastrointestinal tract (GIT). Its misdiagnosis with different diseases is common, however, mimicking or misdiagnosing a GDC as an adrenal cyst has rarely been reported. We report a case of GDC in a young female that was mimicking an adrenal cyst. A 17-year-old female presented with chronic epigastric pain, nausea, and intermittent vomiting. Physical examinations revealed mild tenderness in the epigastric region without abdominal distention, organomegaly, or striae. Oesophagogastroduodenoscopy showed non-significant findings. Transabdominal ultrasound revealed a well-defined, hypoechoic left adrenal cystic lesion. A contrast-enhanced computed tomography scan of the abdomen and pelvis showed an oval-shaped left adrenal cystic lesion measuring 33 x 26 mm. A magnetic resonance imaging scan also confirmed the previous findings. Preoperative blood investigations and hormonal assessment were normal. Laparoscopy was performed and the surgeon intraoperatively noticed that the cyst was originating from the greater curvature of the stomach. The left adrenal gland was normal. An intra-operative consultation with a gastrointestinal surgeon was done, and wedge resection of the cyst was performed. Histopathology confirmed the gastric duplication cyst. The major characteristics for diagnosing GDC include the following: The cyst wall is continuous with the stomach; the cyst is surrounded by a smooth muscle shared with the stomach; both share the same blood supply; and the cyst wall is lined by a benign epithelium. GDCs are rare congenital malformations that may become symptomatic during adulthood. They can mimic adrenal cysts, which may lead to misdiagnosis.