- Human pathology

Home > G. Tumoral pathology > dedifferentiated liposarcoma

dedifferentiated liposarcoma

Monday 5 July 2004



Definition: Dedifferentiated liposarcoma (DLPS) is one of the most frequent sarcomas of the retroperitoneum and represents most undifferentiated sarcomas of the internal trunk.

Dedifferentiated liposarcoma (DLPS) is a member of the group "atypical lipomatous tumor/well-differentiated liposarcoma" (ALT/WDLS), characterized by amplification of MDM2 and CDK4 genes on chromosome 12q13-15 ( MDM2 amplification ).


- dedifferentiated liposarcoma

- dedifferentiated liposarcoma with myxofibrosarcoma-like pattern

- dedifferentiated liposarcoma with meningothelial-like whorls and metaplastic bone formation. FISH: MDM2 amplification

- bronchial dedifferentiated liposarcoma

- digestive dedifferentiated liposarcoma

- pancreatic nodule

Digital cases

- JRC:2531 : Dedifferentiated liposarcoma of soft tissues.
- JRC:2537 : Dedifferentiated liposarcoma, MFH phenotype of soft tissues.
- JRC:320 : Dedifferentiated liposarcoma (with pleomorphic fibrosarcoma appearance) of Soft tissue (thigh).
- JRC:325 : Dedifferentiated liposarcoma, MFH phenotype; Lung (metastasis from a soft tissue tumor from the thigh).
- JRC:15066 : Called c/w MPNST It looks to me like dedifferentiated liposarcoma with neural-like whorling and metaplastic bone formation (Soft tissue, retroperitoneum).
- JRC:15071 : Soft tissue, peritoneum (cul-de-sac) : Dedifferentiated liposarcoma.
- JRC:15240 : Peritoneum (retroperitoneum) : Dedifferentiated liposarcoma (with MPNST look).

DDLPS are biphasic neoplasms occurring in the same age group as WD-LPS, with one component being a WD-LPS and the other a non-lipogenic sarcoma of variable histological grade.

About 90% of DDLPS arise de novo, while 10% occur in recurrence. This histological subtype is found mostly in the retroperitoneum and has a more aggressive behavior than WDLPS with an estimated 5-year disease-specific survival of 44% versus 93%.

The local recurrence rate for retroperitoneal tumors can reach 80% and distant metastatic relapse is observed in up to 30% of cases.


In about 5% cases, the dedifferentiated component is an heterologous sarcoma such as leiomyosarcoma or rhabdomyosarcoma.

- dedifferentiated liposarcoma with rhabdomyoblastic differentiation (16012847)
- dedifferentiated liposarcoma with "homologous" lipoblastic differentiation (pleomorphic liposarcoma-like) (20588177)


- Cytogenetic anomalies similar to those seen in atypical lipomatous tumor/well-differentiated liposarcoma (ALT/WDLS)

- STAT6 is amplified in a subset of dedifferentiated liposarcoma. (24457460)

Differential diagnosis

- Atypical lipomatous tumor/well-differentiated liposarcoma (ALT-WDLPS) and dedifferentiated liposarcoma (DDLPS) may be difficult to distinguish from benign adipose tumors and from poorly differentiated sarcomas, respectively.

  • Genetically, they are characterized by amplification of MDM2 and CDK4 genes on chromosome 12q13-15.
  • MDM2 and CDK4 immunostainings are particularly useful to separate ALT-WDLPS from the large group of differentiated adipose tumors, and to distinguish DDLPS from poorly differentiated sarcomas.
  • A strong correlation was observed between MDM2 and CDK4 stainings and gene amplification status.
  • MDM2 and CDK4 immunostainings, which correlate with gene amplification, are helpful adjuncts to differentiate ALT-WDLPS from benign adipose tumors and to separate DDLPS from poorly differentiated sarcomas.

- undifferentiated high-grade pleomorphic sarcoma (UHGPS)

  • Dedifferentiated liposarcoma (DDL), occurring in up to 10% of well differentiated liposarcoma cases, has similar histologic features to that of undifferentiated high-grade pleomorphic sarcoma (UHGPS).
  • The former develops in a background of atypical lipomatous tumors/well differentiated liposarcoma, whereas the latter shows no specific line of differentiation.
  • The retroperitoneum and thigh represent the most common anatomic locations for both the sarcomas. (19574885)

- myxoid tumors

  • myxoid sarcomas
    • myxofibrosarcoma

See also

- well-differentiated liposarcoma (WD-LPS)

Open References

- STAT6 is amplified in a subset of dedifferentiated liposarcoma. Doyle LA, Tao D, Mariño-Enríquez A. Mod Pathol. 2014 Jan 24. doi : 10.1038/modpathol.2013.247 PMID: 24457460 (Free)

Paywall References

- Can MDM2 and CDK4 make the diagnosis of well differentiated/dedifferentiated liposarcoma? An immunohistochemical study on 129 soft tissue tumours. 2009.

- Dedifferentiated liposarcoma with "homologous" lipoblastic (pleomorphic liposarcoma-like) differentiation: clinicopathologic and molecular analysis of a series suggesting revised diagnostic criteria. Mariño-Enríquez A, Fletcher CD, Dal Cin P, Hornick JL. Am J Surg Pathol. 2010 Aug;34(8):1122-31. PMID: 20588177

- Overlapping Features Between Dedifferentiated Liposarcoma and Undifferentiated High-Grade Pleomorphic Sarcoma. Chung L, Lau SK, Jiang Z, Loera S, Bedel V, Ji J, Weiss LM, Chu PG. Am J Surg Pathol. 2009 Jul 1. PMID: 19574885

- Binh MB, Guillou L, Hostein I, Chateau MC, Collin F, Aurias A, Binh BN, Stoeckle E, Coindre JM. Dedifferentiated Liposarcomas With Divergent Myosarcomatous Differentiation Developed in the Internal Trunk: A Study of 27 Cases and Comparison to Conventional Dedifferentiated Liposarcomas and Leiomyosarcomas. Am J Surg Pathol. 2007 Oct;31(10):1557-1566. PMID: 17895758

- Shimada S, Ishizawa T, Ishizawa K, Kamada K, Hirose T. Dedifferentiated liposarcoma with rhabdomyoblastic differentiation. Virchows Arch. 2005 Nov;447(5):835-41. PMID: 16012847

- Coindre JM, Hostein I, Maire G, Derre J, Guillou L, Leroux A, Ghnassia JP, Collin F, Pedeutour F, Aurias A. Inflammatory malignant fibrous histiocytomas and dedifferentiated liposarcomas: histological review, genomic profile, and MDM2 and CDK4 status favour a single entity. J Pathol. 2004 Jul;203(3):822-30. PMID: 15221942

- Coindre JM, Mariani O, Chibon F, Mairal A, De Saint Aubain Somerhausen N, Favre-Guillevin E, Bui NB, Stoeckle E, Hostein I, Aurias A. Most malignant fibrous histiocytomas developed in the retroperitoneum are dedifferentiated liposarcomas: a review of 25 cases initially diagnosed as malignant fibrous histiocytoma. Mod Pathol. 2003 Mar;16(3):256-62. PMID: 12640106