Incidental finding of a large renal mass on Tc-99m MDP bone scintigraphy.

The bone scan is one of the most frequently performed investigations in a nuclear medicine department. Although such an examination is carried out to evaluate specific symptoms or disease, incidental findings can reveal other pathologic conditions as well. Because Tc-99m methylene diphosphonate (MDP) is excreted by the kidneys, the most common incidental findings are related to renal disease, and in this case a renal mass was seen.