Retroperitoneal Ciliated Foregut Duplication Cyst in a 5-Month-Old Infant: A Case Report

Retroperitoneal ciliated foregut cysts are a rare developmental anomaly arising from abnormal budding of the primitive foregut, with only a few cases documented in the literature. A 5-month-old preterm infant, born at 31 weeks, presented with worsening respiratory distress and hypoxia. Antenatal scanning did not detect abdominal cysts. Medical history was significant for trisomy 21, secundum atrial septal defect, and chronic lung disease of prematurity. At presentation the patient exhibited progressive tachypnoea and desaturation. During evaluation, imaging revealed an incidental large multiloculated retroperitoneal cyst extending from the subphrenic region to the right iliac fossa. Magnetic resonance imaging demonstrated a well-defined cyst measuring 10.5 × 6.5 × 5.2 cm. A decision was made to proceed with laparoscopic excision. Intraoperatively, a large retroperitoneal cyst and a second smaller non-communicating cyst were identified. With careful dissection, complete excision was achieved and the cysts were aspirated. Histopathology confirmed a foregut duplication cyst with respiratory-type epithelium. The postoperative course was uneventful, and the patient made a full recovery and was discharged home one week later. One-year follow-up confirmed complete resolution with no recurrence. Ciliated foregut duplications should be included in the differential diagnosis of children with retroperitoneal cysts. Laparoscopic resection may be a feasible surgical approach.