Pediatric Musculoskeletal Rhabdomyosarcoma

  • Etiology: malignant neoplasm of striated muscle arising from primitive, undifferentiated mesenchymal cells committed to develop into striated muscle
  • Imaging: osseous erosion common
  • MRI: intermediate to hypointense on T1WI, intermediate to hyperintense on T2WI, enhances heterogeneously, often has areas of necrosis, prominent high-flow vessels may be present in alveolar subtype, improved conspicuity on DWI
  • Complications: metastasis to lung
  • Clinical: most common soft tissue sarcoma in children, 50% head and neck / 30% genitourinary / 20% musculoskeletal, embryonal cell type seen in infants is most common, alveolar cell type seen in older children and affects musculoskeletal system and is more aggressive, orbital has best prognosis

Radiology Cases of Musculoskeletal Rhabdomyosarcoma

CXR and CT of rhabdomyosarcoma of the chest wall
CXR PA and lateral (above) shows an ill defined left-sided pleural-based process. Axial CT without contrast of the chest (below) shows a mass arising from the muscles of the left chest wall which invades up into the pleural space and down into the abdomen, sparing the ribs.