Histopathology 2014, 64, 1
Editorial Annual Review Issue: Soft Tissue Tumour Pathology DOI: 10.1111/his.12335
There have been remarkable advances in soft tissue tumour pathology over the 8 years since the inaugural Annual Review Issue in Histopathology, which was also devoted to this challenging area of diagnostic pathology. Not only have many new ‘entities’ been described, but the clinical armamentarium of diagnostic immunohistochemical markers continues to expand, in part owing to the introduction of lineage-restricted transcription factors, as well as the application of gene expression profiling to the challenge of discriminating among histologically similar tumour types. Furthermore, genetic alterations underlying the pathogenesis of soft tissue tumours continue to be elucidated. In most such instances, the genetic findings have served to support our existing histologic classification. However, in some circumstances, discoveries of new mutations have illuminated previously obscure distinctions between sarcomas within a particular histologic class. With the advent of targeted therapies directed against molecular alterations in sarcomas, accurate histologic classification remains of critical importance, and for some sarcoma types, predictive genomic testing has become part of clinical practice. As guest editors of this Annual Review Issue, we have invited a group of renowned experts to update some of the most interesting topics in this diverse field of human neoplasia. In the first article in this issue, Christopher Fletcher provides an overview of the important changes in the classification of soft tissue tumours from the 2002 World Health Organization classification introduced recently in the 2013 WHO classification. This is followed by a review of the evolution of ‘fibrosarcoma’ by Andrew Folpe, including both historical context and our contemporary understanding with the aid of cytogenetics and molecular genetics. Cristina Antonescu then provides an update of round cell sarcomas, illustrating the power of genomic analysis to identify new tumour types previously buried within the confusing ‘wastebasket’ of (non-Ewing) undifferentiated round cell sarcomas. Paolo Dei Tos covers the groups of tumours classified as liposarcomas, emphasizing the integration of immunohistochemistry and molecular genetics with conventional histologic examination in differential diagnosis. The diagnosis and treatment of gastrointestinal stromal tumours (GISTs) © 2013 John Wiley & Sons Ltd.
have evolved considerably over the past 15 years since the initial discovery of activating mutations in the tyrosine kinase receptor gene KIT; Leona Doyle and Jason Hornick provide an overview of the pathogenesis and treatment of these tumours, focusing on the recently discovered class of GISTs characterized by dysfunction of the succinate dehydrogenase enzyme complex. Surgical pathologists play a critical role in identifying familial cancer predisposition syndromes. Cheryl Coffin and colleagues review the syndromes associated with soft tissue tumours, focusing on how pathologists can recognise and help diagnose patients affected by such disorders. This is followed by an overview of the conceptually challenging area of rarely metastasising (‘intermediate biologic potential’) soft tissue tumours, which includes diverse and distinctive tumour types, by Chas Mangham and Lars-Gunnar Kindblom; the histologic and molecular genetic features of several of these tumours have only recently been properly characterised. Immunohistochemistry continues to hold a central position in soft tissue tumour diagnosis; Markku Miettinen reviews some of the most important immunohistochemical markers, which are indispensable for the surgical pathologist. The last four reviews focus on the molecular genetics of soft tissue tumours. Alex Lazar and colleagues discuss the key roles of the pathologist in identifying appropriate patients for new targeted therapies, both in terms of proper diagnosis and molecular genetic characterisation of sarcomas. Soft tissue (and bone) tumours with EWSR1 gene rearrangements include an ever-expanding, clinically and pathologically diverse list of lesions. This interesting group of tumours is reviewed by Cyril Fisher. The final two articles emphasise new techniques, in particular massively parallel (‘next generation’) sequencing. Fredrik Mertens and Johnbosco Tayebwa provide an update on how such approaches can be applied to gene fusion discovery; Matt van de Rijn and colleagues discuss such forms of molecular analysis on paraffinembedded tissue. We trust the readers of Histopathology will find this diverse set of excellent review articles helpful and informative, both for improving clinical practice in diagnostic surgical pathology and understanding the evolving diagnostic and therapeutic roles of molecular genetic analysis for soft tissue tumours. Jason L Hornick D Chas Mangham
Editorial Annual Review Issue: Soft Tissue Tumour Pathology DOI: 10.1111/his.12335
There have been remarkable advances in soft tissue tumour pathology over the 8 years since the inaugural Annual Review Issue in Histopathology, which was also devoted to this challenging area of diagnostic pathology. Not only have many new ‘entities’ been described, but the clinical armamentarium of diagnostic immunohistochemical markers continues to expand, in part owing to the introduction of lineage-restricted transcription factors, as well as the application of gene expression profiling to the challenge of discriminating among histologically similar tumour types. Furthermore, genetic alterations underlying the pathogenesis of soft tissue tumours continue to be elucidated. In most such instances, the genetic findings have served to support our existing histologic classification. However, in some circumstances, discoveries of new mutations have illuminated previously obscure distinctions between sarcomas within a particular histologic class. With the advent of targeted therapies directed against molecular alterations in sarcomas, accurate histologic classification remains of critical importance, and for some sarcoma types, predictive genomic testing has become part of clinical practice. As guest editors of this Annual Review Issue, we have invited a group of renowned experts to update some of the most interesting topics in this diverse field of human neoplasia. In the first article in this issue, Christopher Fletcher provides an overview of the important changes in the classification of soft tissue tumours from the 2002 World Health Organization classification introduced recently in the 2013 WHO classification. This is followed by a review of the evolution of ‘fibrosarcoma’ by Andrew Folpe, including both historical context and our contemporary understanding with the aid of cytogenetics and molecular genetics. Cristina Antonescu then provides an update of round cell sarcomas, illustrating the power of genomic analysis to identify new tumour types previously buried within the confusing ‘wastebasket’ of (non-Ewing) undifferentiated round cell sarcomas. Paolo Dei Tos covers the groups of tumours classified as liposarcomas, emphasizing the integration of immunohistochemistry and molecular genetics with conventional histologic examination in differential diagnosis. The diagnosis and treatment of gastrointestinal stromal tumours (GISTs) © 2013 John Wiley & Sons Ltd.
have evolved considerably over the past 15 years since the initial discovery of activating mutations in the tyrosine kinase receptor gene KIT; Leona Doyle and Jason Hornick provide an overview of the pathogenesis and treatment of these tumours, focusing on the recently discovered class of GISTs characterized by dysfunction of the succinate dehydrogenase enzyme complex. Surgical pathologists play a critical role in identifying familial cancer predisposition syndromes. Cheryl Coffin and colleagues review the syndromes associated with soft tissue tumours, focusing on how pathologists can recognise and help diagnose patients affected by such disorders. This is followed by an overview of the conceptually challenging area of rarely metastasising (‘intermediate biologic potential’) soft tissue tumours, which includes diverse and distinctive tumour types, by Chas Mangham and Lars-Gunnar Kindblom; the histologic and molecular genetic features of several of these tumours have only recently been properly characterised. Immunohistochemistry continues to hold a central position in soft tissue tumour diagnosis; Markku Miettinen reviews some of the most important immunohistochemical markers, which are indispensable for the surgical pathologist. The last four reviews focus on the molecular genetics of soft tissue tumours. Alex Lazar and colleagues discuss the key roles of the pathologist in identifying appropriate patients for new targeted therapies, both in terms of proper diagnosis and molecular genetic characterisation of sarcomas. Soft tissue (and bone) tumours with EWSR1 gene rearrangements include an ever-expanding, clinically and pathologically diverse list of lesions. This interesting group of tumours is reviewed by Cyril Fisher. The final two articles emphasise new techniques, in particular massively parallel (‘next generation’) sequencing. Fredrik Mertens and Johnbosco Tayebwa provide an update on how such approaches can be applied to gene fusion discovery; Matt van de Rijn and colleagues discuss such forms of molecular analysis on paraffinembedded tissue. We trust the readers of Histopathology will find this diverse set of excellent review articles helpful and informative, both for improving clinical practice in diagnostic surgical pathology and understanding the evolving diagnostic and therapeutic roles of molecular genetic analysis for soft tissue tumours. Jason L Hornick D Chas Mangham
