A 7-year-old Hispanic boy with acute onset of abdominal pain.

Editor’s note: Each month, this department features a discussion of an unusual diagnosis in genetics, radiology, or dermatology. A description and images are presented, followed by the diagnosis and an explanation of how the diagnosis was determined. As always, your comments are welcome via email at [email protected]. For diagnosis, see page xxx Apreviously healthy 7-year-old Hispanic boy presented with acute onset of abdominal pain to our emergency department (ED). Intermittent pain was referred to the mid-epigastric region lasting between 5 and 10 minutes, followed by a 20to 30-minute period of calm. The pain did not radiate and improved with kneesto-chest positioning. Several episodes of emesis were associated with painful cramps. The parent denied any recent fever, diarrhea, headache, or rashes on the body. His medical history did not include constipation, recent abdominal injury, chronic gastrointestinal disease, abdominal surgery, or urinary tract infections. Upon arrival to the ED, the child’s physical examination revealed a healthy-looking, well-nourished child. His abdomen was soft and nondistended. Bowel sounds were present. No mass or hernia was palpable. Cardiopulmonary and neurologic exams were unremarkable. ED diagnostic work-up included an abdominal ultrasound that revealed a distinct concentric intestinal image in the left lower quadrant (Figure 1). This “doughnut-like” structure measured 2.5 cm in width (external ring approximately 0.7 cm) with normal blood perfusion on color Doppler (Figure 2).