The Evolving Classification of Soft Tissue Tumors


With the advent of the new format for WHO tumor classifications, there have been major changes in each of the most recent volumes (2002 and 2013) concerning soft tissue neoplasms. Perhaps foremost has been the disappearance of "malignant fibrous histiocytoma" and "hemangiopericytoma." In 2013, the category of undifferentiated sarcomas was introduced, and a large amount of new genetic data across many tumor types was incorporated. Even since the completion of the latest volume (which was published almost a year after the consensus meeting at which the content was finalized), there have been important new findings in solitary fibrous tumor, a subset of rhabdomyosarcomas and among round cell sarcomas. Increasing genetic overlap among seemingly distinct tumour types is emerging and, in the future, the relative importance of phenotype vs. genotype will need to be determined. There also remain opportunities to address significant nomenclatural problems.

Originally presented on November 05, 2015, in Salt Lake City, Utah.

Lecture Presenter

Christopher, D.M. Fletcher, MD, FRCPath

Christopher, D.M. Fletcher, MD, FRCPath

Professor of Pathology
Harvard Medical School
Vice Chair for Anatomic Pathology
Brigham and Women's Hospital, Boston, Massachusetts
Chief of Onco-Pathology
Dana-Farber Cancer Institute

Christopher, D.M. Fletcher, MD, FRCPath, graduated from St. Thomas's Hospital Medical School in London and obtained postgraduate qualifications from the Royal College of Pathologists (MRCPath-1988) and the University of London (MD-1991) in the United Kingdom. He received his training in pathology at St. Thomas's Hospital/United Medical & Dental Schools in London, U.K. Dr. Fletcher's main areas of interest include the clinicopathologic and molecular genetic analyses of soft tissue tumors. Dr. Fletcher has published extensively on the pathology of soft tissue tumors and is probably best known for his work challenging the diagnostic entities of malignant fibrous histiocytoma and hemangiopericytoma. He has also for the first time described a variety of lesions, including, among others, deep benign fibrous histiocytoma, angiomyofibroblastoma, retiform hemangioendothelioma, spindle cell liposarcoma, myoepithelial lesions of soft tissue, cellular angiofibroma and soft tissue angiofibroma. He has worked extensively on cytogenetic/morphologic correlations in soft tissue tumors. He is chairman of the WHO Working Group on the classification of soft tissue tumors, having been senior editor of both the 2002 and most recent 2013 classifications. He has nearly 600 publications, including more than 400 original papers on soft tissue neoplasms, and several books, among which are the two-volume Diagnostic Histopathology of Tumors, the 4th edition of which was published in Spring 2013, and the 3rd series AFIP Fascicle on Soft Tissue Tumors. He has been the recipient of numerous honors and awards (including most recently the Harvey Goldman Distinguished Teacher & Mentor award of the USCAP), is on the editorial board of 17 international journals and was president of the Association of Directors of Anatomic and Surgical Pathology for two terms from 2003 to 2006. More recently he has been president of the International Society of Bone & Soft Tissue Pathology and the president of the Arthur Purdy Stout Society, and is currently vice-president of the USCAP. Before moving to the United States in 1995, Dr. Fletcher was the director of the Soft Tissue Tumor Unit at St. Thomas's Hospital in London and professor of surgical pathology in the University of London; he is currently professor of pathology at Harvard Medical School, vice chair for anatomic pathology at Brigham and Women's Hospital, Boston, Massachusetts and chief of Onco-Pathology at the Dana-Farber Cancer Institute in Boston.


After this presentation, participants will be able to:

  • Attendees will better understand the relevance of (and rationale for) changes made in the 2013 WHO Classification of Soft Tissue Tumors.
  • Attendees will more clearly appreciate the role of cytogenetic and molecular genetic testing in diagnosis and classification of soft tissue tumors, along with the challenges that these data bring.
  • Attendees will recognize why the classification of soft tissue tumors continues to evolve.

Sponsored by:

University of Utah School of Medicine, Department of Pathology, and ARUP Laboratories