Case report: a rare cause of chronic abdominal pain and failure to thrive in a child — extensive gastrointestinal tract duplication cyst

Abstract Background Gastrointestinal tract duplication cyst is a rare congenital anomaly and can occur anywhere along the alimentary tract. Clinical presentation depends on the size, location, and type of mucosa lining the cyst, from asymptomatic to severe disease such as bleeding, infection, or malignant transformation. We report a case of an extensive enteric duplication cyst involving the terminal ileum, small bowel mesentery, and retroperitoneum. Case presentation An 8-year-old boy with a history of chronic abdominal pain and iron deficiency anemia presented to the pediatric outpatient clinic for worsening abdominal pain and vomiting for 3 days. He was pale with hemoglobin of 7.2 g/dL. On examination, his abdomen was soft but tender over epigastric region with no palpable mass. Ultrasound showed thickened bowel loops in the left half of the abdomen with hyperechoic inner rim and hypoechoic outer wall. A provisional diagnosis of enteritis was made, and the patient was treated with antibiotics. Abdominal pain persisted despite treatment; hence, a contrast-enhanced computed tomography of the abdomen was done which showed a bowel-like structure occupying the right lumbar region, crossing the midline, and extending into the left lumbar and left hypochondriac region retroperitoneally. The small bowel follow-through showed flow of contrast from the small bowel loops to the rectum. There was no opacification or contrast retention within the bowel-like structure. Imaging findings were suggestive of enteric duplication cyst. The patient underwent a laparotomy, and operative findings confirmed the diagnosis of an extensive tubular duplication. Histopathological report showed bowel duplication with heterotopic gastric mucosa. The duplicated bowels were completely excised, and patient recovered well after surgery. Conclusion Clinical presentation of bowel duplication is nonspecific and can mimic symptoms of chronic gastritis. A high index of suspicion is needed to differentiate a duplicated bowel from normal bowels on ultrasound. Computed tomography is helpful in doubtful and complicated cases for anatomical delineation and planning of surgical approach. Diagnosis is usually confirmed intraoperatively and through histopathological examination. Total surgical excision is curative with good prognosis.