Foregut duplication cysts: a report of two cases with emphasis on embryogenesis.

Duplication cyst of the stomach with a pseudostratified columnar ciliated epithelium is extremely rare. We describe two cases of these cysts, with emphasis on their immunophenotype and embryogenesis. The first patient was a 29-year-old man who presented with cramping abdominal pain in his left lower quadrant. The second patient was a 26-year-old woman who had a history, over several years, of chronic epigastric abdominal pain radiating to her back. Both lesions were surgically removed. They showed the same histomorphology. The cysts were lined by a pseudostratified respiratory epithelium with ciliated cells. The first cyst was connected to the stomach, while the second cyst was not connected. Both cysts expressed thyroid transcription factor-1 (TTF-1) and surfactant. In this report, we explore the possible embryogenesis of these lesions in the light of TTF-1 and surfactant expression.