Soft tissue
Adipose tissue tumors
Other benign lesions
Lipoblastoma / lipoblastomatosis


Topic Completed: 1 August 2012

Minor changes: 28 September 2020

Copyright: 2002-2020, PathologyOutlines.com, Inc.

PubMed Search: Lipoblastoma / lipoblastomatosis

Vijay Shankar, M.D.
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Cite this page: Shankar V. Lipoblastoma / lipoblastomatosis. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/softtissueadiposelipoblastoma.html. Accessed October 24th, 2020.
Definition / general
  • Lobulated tumor, either localized (lipoblastoma) or diffuse (lipoblastomatosis), resembling fetal adipose tissue
Terminology
  • Lipoblastoma: also called fetal/embryonal lipoblastoma; well circumscribed and subcutaneous
  • Lipoblastomatosis: deep-seated and ill-defined
Epidemiology
  • Rare
  • Infants and young children age 3 years or less (rarely ages 14 - 24 years)
  • 80% are boys
Sites
  • Extremities, trunk, head and neck
  • Occasionally mediastinum, retroperitoneum or inguinal region, thigh, parotid region, scrotum, intrathoracic region
Clinical features
  • Usually presents as painless superficial soft tissue mass, 75% on left side
  • If not removed, matures into lipoma but with prominent fibrous septa
  • FISH is helpful to confirm diagnosis (Histopathology 2008;52:294)
Case reports
Treatment
Clinical images

Images hosted on other servers:

Lobulated and encapsulated tumor

Gross images

Contributed by Mark R. Wick, M.D.



Images hosted on other servers:

Large white mass

Microscopic (histologic) description
  • Hypocellular lobules of adipocytes in various stages of differentiation including preadipocytes (spindle or stellate shaped), uni- or multi-vacuolated lipoblasts and mature adipocytes in central lobule
  • Separated by prominent fibrous septa that may be cellular
  • Has plexiform vascular pattern and abundant myxoid stroma
  • May have prominent extracellular mucinous pools
  • Resembles fetal fat and myxoid liposarcoma
  • Lipoblastomatosis: less lobulation; infiltrates skeletal muscle
Microscopic (histologic) images

Contributed by Mark R. Wick, M.D.



Case #123

1 year old boy with neck mass



AFIP images

Lobular architecture with prominent fibrous septa

Plexiform vascular pattern with myxoid matrix and small fat cells

Resembles lipoma with minimal myxoid stroma



Images hosted on other servers:

Various images

Scapula tumor

Cytology description
  • Moderate to poorly cellular
  • Clusters of lipocytes, lipoblasts, spindle cells
  • Background of myxoid material and naked oval nuclei (Diagn Cytopathol 2005;33:195)
Cytology images

Case #123

1 year old boy with neck mass

Electron microscopy description
  • Cells have investing basal lamina, pinocytotic vesicles, Golgi membranes, round / oval mitochondria, cytoplasmic glycogen and cytoplasmic lipid (Am J Surg Pathol 1980;4:163)
  • Resembles myxoid liposarcoma and normal developing fat
Molecular / cytogenetics description
Molecular / cytogenetics images

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FISH / CISH of PLAG1 gene

Differential diagnosis
Additional references
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