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What’s new in adipocytic neoplasia?

  • David CreytensEmail author
Review Article

Abstract

Adipocytic tumors are frequently encountered in routine practice, and while the vast majority represent commonly encountered tumor types (e.g., benign lipoma), the heterogeneity and rarity of other adipocytic neoplasms can pose diagnostic challenges. Atypical and malignant adipocytic tumors account for approximately 20% of all sarcomas. The 2013 World Health Organization (WHO) classification of soft tissue and bone tumors recognizes four major liposarcoma subtypes, characterized by distinct clinical behavior, distinctive morphologies, as well as unique genetic findings: atypical lipomatous tumor/well-differentiated liposarcoma, dedifferentiated liposarcoma, myxoid liposarcoma, and pleomorphic liposarcoma. Since the publication of the 2013 WHO classification of soft tissue and bone tumors, the most notable change in the category of adipocytic tumors has been made in the clinicopathologic and molecular characterization of the heterogeneous but distinct group of “atypical low-grade adipocytic neoplasms with spindle cell features,” for which the term atypical spindle cell/pleomorphic lipomatous tumor has been proposed. Another substantive change in the group of adipocytic tumors is the introduction of pleomorphic myxoid liposarcoma (myxoid pleomorphic liposarcoma) as an apparently novel subtype of aggressive liposarcoma, especially occurring in children and young adults with a predilection for the mediastinum. This review will further focus upon the diagnostic criteria of these novel emerging entities in the group of adipocytic tumors.

Keywords

Atypical spindle cell/pleomorphic lipomatous tumor Spindle cell/pleomorphic lipoma Pleomorphic myxoid liposarcoma Pleomorphic liposarcoma RB1 MDM2 

Notes

Compliance with ethical standards

The author has complied with all ethical standards as outlined on the Virchows Archives website.

Conflict of interest

The author declares that he has no conflicts of interest.

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Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  1. 1.Department of PathologyGhent University and Ghent University HospitalGhentBelgium

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