Soft tissue
Adipose tissue
Pleomorphic liposarcoma

Author: Vijay Shankar, M.D. (see Authors page)

Revised: 9 August 2016, last major update August 2012

Copyright: (c) 2002-2016, PathologyOutlines.com, Inc.

PubMed Search: Pleomorphic liposarcoma [title]

Cite this page: Pleomorphic liposarcoma. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/softtissueadiposepleomorphiclipo.html. Accessed December 5th, 2016.
Definition / General
  • Widespread high grade, pleomorphic tumor cells with some lipoblasts but no evidence of well differentiated liposarcoma
Epidemiology
  • 5% of all liposarcomas
  • No gender preference
  • Median age 54 - 70 years; rare in childhood
  • Associated with radiation therapy or neurofibromatosis
Sites
  • Thigh (29%), internal trunk (21%), limb girdles (18%), upper extremity (16%), thoracoabdominal wall (10%)
  • Often deep seated or extracompartmental
Case Reports
Treatment
  • Wide local excision or amputation with postoperative radiotherapy (Am J Surg Pathol 2004;28:1257), also chemotherapy
  • Aggressive; often recurs locally (40%), metastasizes (40%), causes death (35%)
  • 5 year overall survival 60%
  • Poor prognostic factors: age 60+, truncal (central) location, deep, size > 5 cm, vascular invasion, incomplete excision (Am J Surg Pathol 2002;26:601)
Clinical Images

Images hosted on other servers:

Pectoral wall mass

Gross Description
  • Often large (median 8 - 10 cm, up to 23 cm), multinodular, white-yellow
  • Areas of hemorrhage and necrosis common
  • Usually deep (subfascial), often myxoid or necrotic areas
Gross Images

Images hosted on other servers:

Upper arm

Infiltrating gluteus muscle

Retroperitoneum

Micro Description
  • Well circumscribed but non-encapsulated with infiltrative borders
  • At least focal typical liposarcomatous areas
  • Pleomorphic cells cover > 65% of cut surface with MFH-like, round cell liposarcoma-like (without vascular network), spindle cell liposarcoma-like or epithelioid cells (Mod Pathol 1999;12:722)
  • Usually high grade with enlarged round to bizarre nuclei
  • Tumor necrosis common
  • Median 25 mitotic figures / 10 HPF
  • May have neutrophils within giant cells, hemangiopericytic foci, extra- and intracellular hyaline droplets
  • Epitheloid variant often confused with carcinoma
Micro Images

Images hosted on PathOut servers:

Lipoblasts present

Vacuolated lipoblasts

Myxoid stroma with markedly pleomorphic cells

Pleomorphic round cells

MFH-like areas



Courtesy of Mark R. Wick, M.D.



Images hosted on other servers:

Various images

Retroperitoneum



Pectoral wall

Pleomorphic lipoblasts

MFH-like areas

Comparison with pleomorphic rhabdomyosarcoma

Cytology Description
  • Pleomorphic spindle cells of high grade sarcoma with occasional lipoblasts
Positive Stains
Electron Microscopy Description
  • Abundant coalescing lipid droplets, numerous cytoplasmic organelles
Molecular / Cytogenetics Description
  • Complex karyotype
  • Shares similar genomic imbalances with myxofibrosarcoma (Lab Invest 2005;85:176)
  • Epithelioid variant rarely has t(12;16)(q13;p11) - TLS-CHOP, more commonly seen in myxoid and round cell liposarcoma (Histopathology 2005;46:334)
Differential Diagnosis