ABSTRACT
A 4-year-old boy, whose only significant past medical history was a tonsillectomy 1 year prior, presents with a 5-day history of constipation and urinary incontinence. He had been completely toilet-trained. In the emergency room, he is found to have significant abdominal distention without tenderness. The emergency department physician palpates a mass in the lower abdomen and orders an ultrasound. The study, shown in Figure 55.1, demonstrates a very large heterogeneous solid mass filling the pelvis and extending into the left lower abdomen. The mass displaces the bladder to the right. There is mild hydronephrosis bilaterally, but the kidneys are otherwise normal.
