Intense accumulation of Tc-99m MDP in pericardial metastasis from breast cancer.

Extraosseous uptake often seen on Tc-99m methylene diphosphonate bone scintigraphy has clinical significance. In a routine follow-up study on a 54-year-old female patient with breast cancer, we encountered a rare finding of pericardial metastasis clearly demonstrated by Tc-99m methylene diphosphonate bone scintigraphy. This incidental finding of increased uptake in the periphery of the cardiac contour on a bone scan reflects radionuclide accumulation in pericardium, myocardium, or pericardial effusion itself. In our case, an additional computed tomography examination of the chest was useful for making the definitive diagnosis of dystrophic calcification of the pericardium.