Abdominal scanning with Tc-99m red blood cells. False-positive study due to ectopic kidney.

Abdominal scanning with Tc-99m red blood cells performed in a patient with gastrointestinal bleeding demonstrated a localized area of increased activity in the pelvic region that simulated either bleeding in a mass or encapsulated bleeding. Contrast angiography confirmed that the bleeding was due to a right ectopic kidney.