Annular Pancreas Presenting with Intermittent Duodenal Obstruction in Early Childhood: A Diagnostic Masquerade.

Background and Clinical Significance: Annular pancreas is a rare congenital anomaly in which pancreatic tissue partially or completely encircles the duodenum, potentially causing duodenal obstruction. Clinical presentation varies from asymptomatic cases to persistent vomiting, feeding intolerance, and failure to thrive, often leading to delayed diagnosis. Case Presentation: We report a 2-year and 10-month-old girl with a long-standing history of intermittent, recurrent vomiting since the neonatal period, without growth impairment or other alarming symptoms. Initial imaging suggested proximal duodenal dilation, with suspicion for superior mesenteric artery (SMA) syndrome. Endoscopy revealed mechanical obstruction at the second portion of the duodenum. Contrast-enhanced CT confirmed annular pancreas partially encircling the duodenum. The patient underwent duodeno-duodenostomy with an uneventful postoperative course and complete resolution of symptoms. This case illustrates the diagnostic challenges of annular pancreas in older children with atypical presentations. Multimodal imaging is crucial for accurate diagnosis. Surgical bypass remains the definitive treatment, offering excellent long-term outcomes. Conclusions: Persistent or recurrent vomiting in children, even without classic signs such as bilious vomiting or failure to thrive, should prompt consideration of annular pancreas. Early recognition and timely surgical intervention can prevent prolonged morbidity and ensure normal growth and development.