Foregut duplication of the stomach diagnosed by endoscopic ultrasound guided fine-needle aspiration cytology: case report and literature review.

Gastric duplication cyst (GDC) with a pseudostratified columnar ciliated epithelium is an uncommon malformation supposed to originate from a respiratory diverticulum arising from the ventral foregut. Morphologic appearance of GDCs is variable, depending on the density of their contents. GDCs are often misdiagnosed as solid masses by imaging techniques, and as a consequence they may be wrongly overtreated. We report our case of a 56-year-old man with a 5 cm hypoechoic mass of the gastroesophageal junction, incidentally detected by transabdominal ultrasonography. Neither transabdominal ultrasonography nor magnetic resonance clearly outlined the features of the lesion. The patient underwent endoscopic ultrasound (EUS), which showed a hypoechoic mass arising from the fourth layer of the anterior gastric wall, just below the gastroesophageal junction. According to EUS features, a diagnosis of gastrointestinal stromal tumor was suggested. EUS-guided fine-needle aspiration cytology revealed a diagnosis of GDC with pseudostratified columnar ciliated epithelium. We therefore performed an endoscopically-assisted laparoscopic excision of the cyst.In conclusion, whenever a subepithelial gastric mass is found in the upper part of the gastric wall, a duplication cyst, although rare, should be considered. In this case, EUS-guided fine-needle aspiration cytology could provide a cytological diagnosis useful to arrange in advance the more adequate surgical treatment.