Tc-99m MDP uptake on bone scintigraphy by a giant rhabdomyosarcoma involving the lower extremity in an elderly woman

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children. However, RMS rarely affects adults. A 68-year-old woman was admitted for evaluation of a huge mass in the left lower leg. A biopsy confirmed RMS. Tc-99m MDP bone scintigraphy was obtained to evaluate bone metastases, and diffusely increased uptake was noted in the huge soft tissue mass of the left lower extremity with linear increased uptake along the left tibia and fibula corresponding to the bony destructive lesion on the radiograph. This case presents extraosseous uptake of Tc-99m MDP by a giant RMS with bone invasion of the left lower extremity in an elderly woman.