Mesenchymal Hamartoma of Chest Wall

  • Etiology: Benign proliferation of skeletal tissue characterized by a prominent cartilaginous component and hemorrhagic cavities (secondary aneurysmal bone cyst) that arises in rib
  • Imaging:
    — Large, extrapleural, partially calcified soft-tissue mass arising from one or more ribs
    — Associated destruction and distortion of adjacent bony thorax
  • DDX:
  • Complications: May cause severe respiratory compromise
  • Treatment: Resection
  • Clinical: Deforming chest wall mass often noticed at birth

Radiology Cases of Mesenchymal Hamartoma of Chest Wall

CXR and CT of mesenchymal hamartoma of chest wall
CXR AP shows a large mass arising from the left 4th-6th ribs. Axial CT without contrast of the chest with soft tissue windows (right upper and middle) show the mass to have a fluid-fluid level within it superiorly while bone windows (right lower) show the mass to be calcified.
CXR and specimen radiograph of mesenchymal hamartoma of the chest wall
CXR AP and lateral (above) show a cystic expansile lesion arising from the posterior aspect of the right 8th rib causing distortion of the adjacent bony thorax. Specimen radiograph (below) shows the partially calcified soft-tissue mass arising from the rib.