The "bat sign" of pectoral rhabdomyolysis

A 22-year-old man with foot pain was referred for evaluation of sesamoiditis. A Tc-99m methylene-diphosphonate bone scan was performed which revealed increased radiopharmaceutical uptake in the big toes, but also showed curious abnormal thoracic activity. Normal activity at sternoclavicular joints and sternum mimics ears, head and body of a bat, and the pectorals mimic the wings. The patient mentioned that he had started lifting weights a few days earlier. Clinical and echographic evaluations were diagnostic of pectoral inflammation suggesting rhabdomyolysis.