Bronchogenic Cyst at the Terminal Ileum Presenting as an Enteric Duplication: A Case Report.

Bronchogenic cysts are congenital foregut malformations most often found in the mediastinum or lung parenchyma. Abdominal locations are exceedingly rare and most commonly found in the left retroperitoneum. They may mimic other intra-abdominal masses and pose a preoperative diagnostic challenge. A 17-year-old female presented with 4 days of diffuse, mild abdominal pain. Ultrasound and MRI identified a 5.5 × 3.8 × 3.1 cm unilocular, hypoechoic cyst adjacent to the terminal ileum at the ileocecal valve. Preoperative differential diagnoses included an ileal duplication cyst. Single-incision laparoscopy was converted to a small open ileocecal resection. Histopathology revealed a bronchogenic cyst, lined with ciliated respiratory epithelium with focal non-keratinized squamous epithelium. The patient recovered uneventfully and remained asymptomatic at 3-week follow-up. Although rare and often detected incidentally, bronchogenic cysts should be considered in the differential diagnosis of abdominal cystic lesions. Complete surgical excision is recommended to establish the diagnosis, relieve symptoms, and prevent potential complications. To our knowledge, this is the first reported case of a bronchogenic cyst located at the terminal ileum.