ROUNDWORM OBSTRUCTION - SONOGRAPHIC DIAGNOSIS

We describe the sonographic findings in five pediatric patients with r oundworm obstruction. All patients were referred with a clinical diagn osis of acute appendicitis. On ultrasonography (US), an individual wor m, when viewed along its longitudinal axis, appeared as a hypoechoic t ubular structure with well-defined, echogenic walls. Frequently, the i ndividual body segments could be distinctly visualized. The alimentary canal of the worm was seen either as a single central echogenic line (when in a collapsed state) or as two parallel hyperechoic bands with a hypoechoic center (when distended). When examined transaxially, the individual worm resembled a target with its circular, echogenic body w all and its central dot-like alimentary canal. On prolonged scanning, the worms always showed curling movements. In two patients, a bolus of worms mixed with fecal matter and air produced an unusual appearance of a complex, echogenic mass (helminthoma). Although, an individual wo rm occasionally resembled an inflammed appendix, visualization of the alimentary canal and individual body segments along with its curling m ovements helped establish the correct diagnosis. All patients promptly responded to a hypertonic saline enema and no patient was subjected t o surgery. Sonographic findings in roundworm obstruction are fairly ch aracteristics to advocate the routine use of sonography for diagnosing this entity.