Lipoblastoma

Clinical features

  • Adipose tissue tumours represent 6% of soft-tissue tumours in paediatric age and lipoblastomas represent 30%
  • 88% of the cases occurs under 3 years
  • More common in boys, in extremities (38-73%), trunk, retroperitoneum (10%), mediastinum and chest
  • Association with malformations, seizures or development delay
  • Recurrence has been reported in up to 25% of cases
  • Deep-seated tumours can give symptoms related to compression of adjacent organs
  • When infiltrative grow, it is called lipoblastomatosis

 

Fig 18a (H&E),  Lipoblastoma - Fragments of adipose tissue, (mixture of fat cells in different stages of maturation) (H&E)
Fig 18b (Giemsa) – Lipoblastoma - Fragments of adipose tissue, (mixture of fat cells in different stages of maturation) (H&E)
Fig 19 – Lipoblastoma -Sheet of immature cells mixed with mature adipose cells (H&E)
Fig 20 – Lipoblastoma –Multivacuolated lipoblasts with scalloped hyperchromatic nuclei. Cells lack Pleomorphism and nuclei have bland chromatin (H&E)
Fig 21 – Lipoblastoma - Numerous lipoblasts (Giemsa)

 

  • Myxoid background
  • Fragments of myxoid stroma, sometimes mixed with adipocytes
  • Fragments of adipose tissue, with a mixture of fat cells in different stages of maturation (central or eccentrically placed nucleus )
  • capillary network is usually present
  • Mesenchymal immature cells
  • Cells with delicate chromatin
  • Nucleoli absent
  • Lipoblasts without nuclear polymorphisms

Genetic Studies

  • Structural rearrangements involving chromosome 8q11-13 region

Differential Diagnosis

Numerous paediatric lesions can have adipose tissue within:

  • Liposarcoma Myxoid (distinction in FNAC is sometimes difficult)
    • Rare lesions in children
    • Atypical lipoblasts
    • Atypical univacuolated cells
    • Abundant characteristic myxoid background
    • Branching capillaries are prominent
    • chromosome rearrangements in the region of 12q14
  • Intramuscular haemangioma
    • Skeletal muscle
    • Mature adipocytes
    • No atypia
  • Intramuscular lipomas
    • Atrophic muscle fibbers
    • Mature adipose cells
  • Nephroblastoma
    • Located in the kidney
    • Presence of mesenchymal, blastemal or epithelial differentiation

Main points

  • Lesions mature as time passes

Surgery is the treatment of choice             

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