A male infant presenting with acute urinary retention

A 3-month-old male infant was admitted to the emergency department for acute urinary retention. A voiding cystourethrogram was performed because urethral valves were suspected. After bladder catheterization, the plain radio - graph prior to filling of the bladder showed an abnormal course of the urinary catheter tip together with focal absence and displacement of bowel gas out of the pelvis. Early contrast opacification of the bladder (Fig. A) demonstrated an abnormal cranial position of the lumen and an extrinsic impression on the bladder base, which became obscured after further distension of the bladder (Fig. B). These findings suggested presence of a pelvic mass, which was confirmed sonographically. CT and MRI were performed for better tumor delineation and tissue characterization. Both demonstrated a sharply delineated presacral soft tissue mass with homogeneous enhancement and DWI showed diffusion restriction. Sagittal T2-weighted image (Fig. C) nicely exhibits upward elevation of the bladder caused by a homogeneous presacral mass. Serum analysis showed increased neuron specific enolase and increased catecholamine metabolites were found in the urine. Tru-cut biopsy specimens confirmed neuroblastoma. CT and MIBG scan revealed no distant sites outside the pelvis while a bone scinti - graphy ruled out bone metastases. The tumor was macroscopically completely removed by means of a median laparotomy, and the infant recovered well after therapy.