Pediatric Lipoblastoma

  • Etiology: Benign tumor arising from embryonic white fat that contains mature and immature adipocytes and myxocollagenous stroma
  • Imaging:
    — Lipoblastoma is well-circumscribed and encapsulated and superficial
    — Lipoblastomatosis is infiltrative and non-encapsulated and deep
  • Imaging MRI:
    — Some contain very little fat
    — Variable amounts of fibrous septae and myxoid matrix determine appearance
    — Indistinguishable from liposarcoma – rely on age to differentiate
  • DDX: Cannot be reliably distinguished from liposarcoma but lipoblastoma is much more common
  • Complications: Metastases rare, locally recurrent (25%)
  • Treatment:
  • Clinical:
    — Less than 3 years old
    — Second most common fatty tumor in children
    — 78% in extremity

Radiology Cases of Lipoblastoma

CXR and CT of lipoblastoma
CXR PA and lateral (above) shows a right sided chest mass in the posterior mediastinum. Axial CT with contrast of the chest (below) shows a homogeneous mass, of fat density, with a few septations, in the right posterior mediastinum causing some anterior displacement of the right mainstem bronchus.