An unusual case of a false-positive iodine-131 whole body scan in a patient with papillary thyroid cancer.

A false-positive I-131 whole body scan (WBS) for lung uptake in a patient with papillary thyroid cancer, with replacement of his infiltrated esophagus with a left colon graft, is presented. The I-131 image, seen in the upper right lung field, was due to the contaminated colon graft lacking normal peristaltic movements, which was located in the right paramediastinal region. This finding was demonstrated by imaging the upper digestive tract with orally administered Tc-99m DTPA and by a barium x-ray.