Rhabdomyolysis of Bilateral Teres Major Muscles

A Tc-99m MDP bone scan was performed to evaluate septic arthritis in a 16-year-old boy with a 2-day history of fever and bilateral shoulder pain, the right more symptomatic than the left. His creatine phosphokinase level was 5, 464 U/I (normal, <120 U/I), and his leukocyte count was 16.7 x 1,000 (normal, 4 to 11 x 1,000). Findings of radiographs of the shoulders were normal. Tracer was abnormally localized in the region of the bilateral teres major muscles. Magnetic resonance imaging confirmed this soft tissue process in the right shoulder. These findings were consistent with rhabdomyolysis. Further questioning revealed that he had recently participated excessively in tennis and swimming, both activities requiring repetitive extension and adduction of the arms, thus involving the teres major muscles.