Bronchogenic cyst of the stomach masquerading as benign stromal tumor.

Gastric bronchogenic cyst is an extremely rare lesion. A 62-year-old Korean woman presented with an incidentally found perigastric nodule. An abdominal ultrasonogram and computed tomography showed a 1.5 cm solid, homogeneous, low-density nodule in the hepatogastric ligament near the gastric lesser curvature. At the time of surgery, a soft 1.7 cm nodule was found in the lesser curvature side just below the gastroesophageal junction, and a gelatinous mass was protruded from the nodule during the resection. Microscopically, the gastric subserosa showed cystic structures lined by pseudostratified ciliated columnar epithelium, seromucinous gland, connective tissue and complete layers of smooth muscle bundles. Neither cartilage nor gastrointestinal epithelium was identified. A mucocele was found near the cyst and foamy cells and faintly bluish mucinous substances were found near the cystic structures. All the mucinous substances were stained by alcian blue at pH 2.5 with varying degrees of staining intensity. The present case is the smallest reported cyst among the gastric bronchogenic cysts, and these lesions are unusually located at the lesser curvature side of the stomach. Although these lesions are very rare, gastric bronchogenic cyst should be included in the differential diagnosis of gastric wall mass.