Accepted Article
Received Date : 16-Aug-2013 Revised Date : 06-Sep-2013 Accepted Date : 06-Sep-2013 Article type : Review
Fibrosarcoma: A Review and Update
Andrew L. Folpe, MD
Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
Address for correspondence: Andrew L. Folpe, M.D., Department of Laboratory Medicine and Pathology, Mayo Clinic, 200 1st Street SW, Rochester, MN 55905. Phone: 507-266-9229, Fax: 507-284-1875, Email: [email protected]
Running title: Fibrosarcoma review
Keywords: Fibrosarcoma, low-grade fibromyxoid sarcoma, sclerosing epithelioid fibrosarcoma, dermatofibrosarcoma protuberans, immunohistochemistry, molecular genetics
This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process which may lead to differences between this version and the Version of Record. Please cite this article as an 'Accepted Article', doi: 10.1111/his.12282 This article is protected by copyright. All rights reserved.
Accepted Article
No competing interests or relevant financial interests.
Abstract Adult fibrosarcoma, defined by the World Health Organization as “malignant neoplasm composed of fibroblasts with variable collagen production and, in classical cases, a ‘herringbone’ architecture”, is a very rare soft tissue sarcoma. Once considered the most common adult sarcoma, the incidence of adult fibrosarcoma has declined dramatically over the past several decades. This is due to 1) evolution in the classification of soft tissue tumors, 2) recognition of clinically, morphologically and genetically distinctive subtypes of fibrosarcoma, and 3) increased understanding of the many other mesenchymal and non-mesenchymal tumors that may mimic fibrosarcoma. This review article will summarize the current state of our knowledge about strictly defined adult fibrosarcoma and discuss important entities in its differential diagnosis, including various fibrosarcoma variants, monophasic synovial sarcoma, and other potential mesenchymal and non-mesenchymal mimics.
Overview This article will review the subject of fibrosarcoma (FS), concentrating on the entity referred to by the World Health Organization as “Adult Fibrosarcoma” 1. This term refers
to a specific entity, which is by definition a diagnosis of exclusion. Fibrosarcomas in children represent a clinicopathologically and genetically distinct entity, and are beyond
This article is protected by copyright. All rights reserved.
Accepted Article
the scope of this article. In addition to adult FS, this article will also address selected other important fibroblastic sarcomas that must be distinguished from adult FS, including low-grade fibromyxoid sarcoma, sclerosing epithelioid fibrosarcoma, and fibrosarcomatous dermatofibrosarcoma protuberans. Other spindle cell malignant neoplasms that enter the differential diagnosis of adult FS, in particular monophasic synovial sarcoma will also be addressed.
Historical Background Adult fibrosarcoma (FS) was once considered to represent far and away the most common soft tissue sarcoma in adults, reportedly accounting for 66% of all sarcomas seen at Mayo Clinic between 1910 and 1930 2. Indeed, Meyerding and colleagues seem
not to have considered the possibility of other tumors mimicking FS. However, this viewpoint began to be challenged, beginning with Dr. Arthur Purdy Stout’s landmark study of FS, published in the first volume of Cancer in 1948 3. Critically, Stout
emphasized the numerous morphologic mimics of FS, including what we would now recognize as variants of liposarcoma, rhabdomyosarcoma, synovial sarcoma, malignant peripheral nerve sheath tumor, and fibromatosis, commenting that “there is little cause for wonder therefore that many malignant sarcomas of other sorts have been reported as fibrosarcomas…” 3. Stout’s observations represent a critical “intellectual leap” in soft tissue pathology, specifically the recognition that FS was inherently a diagnosis of exclusion.
This article is protected by copyright. All rights reserved.
Accepted Article
The impact of Stout’s work is illustrated in 4 subsequent series of FS from the Mayo Clinic. The first major study of FS from Mayo Clinic in the “post-Stout” era, by Pritchard and colleagues in 1974, clearly demonstrates Stout’s influence 4. These authors
reviewed a series of 330 tumors diagnosed as FS between 1910 and 1968 (including Meyerding’s cases) and excluded over 33% as representing something other than FS. Pritchard and co-workers regarded only 12% of soft tissue sarcomas seen at Mayo Clinic during this time period to represent FS 4. Fifteen years later another series of
putative FS from Mayo Clinic (including 87 of 199 cases previously reported by Pritchard et al) again reclassified the majority of these cases as likely representing something other than FS 5. Finally, Bahrami and Folpe’s 2010 series of 163 Mayo Clinic cases previously classified as FS found only 16% to actually represent FS when studied with modern immunohistochemical and molecular genetic techniques 6. Thus, the
incidence of FS has declined dramatically over the past 7 decades, with recent SEER data showing it to account for only 3.6% of sarcomas arising from soft tissues 7. Even
these data overstate the incidence of adult FS, however, and it is likely that strictly defined cases account for
Received Date : 16-Aug-2013 Revised Date : 06-Sep-2013 Accepted Date : 06-Sep-2013 Article type : Review
Fibrosarcoma: A Review and Update
Andrew L. Folpe, MD
Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
Address for correspondence: Andrew L. Folpe, M.D., Department of Laboratory Medicine and Pathology, Mayo Clinic, 200 1st Street SW, Rochester, MN 55905. Phone: 507-266-9229, Fax: 507-284-1875, Email: [email protected]
Running title: Fibrosarcoma review
Keywords: Fibrosarcoma, low-grade fibromyxoid sarcoma, sclerosing epithelioid fibrosarcoma, dermatofibrosarcoma protuberans, immunohistochemistry, molecular genetics
This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process which may lead to differences between this version and the Version of Record. Please cite this article as an 'Accepted Article', doi: 10.1111/his.12282 This article is protected by copyright. All rights reserved.
Accepted Article
No competing interests or relevant financial interests.
Abstract Adult fibrosarcoma, defined by the World Health Organization as “malignant neoplasm composed of fibroblasts with variable collagen production and, in classical cases, a ‘herringbone’ architecture”, is a very rare soft tissue sarcoma. Once considered the most common adult sarcoma, the incidence of adult fibrosarcoma has declined dramatically over the past several decades. This is due to 1) evolution in the classification of soft tissue tumors, 2) recognition of clinically, morphologically and genetically distinctive subtypes of fibrosarcoma, and 3) increased understanding of the many other mesenchymal and non-mesenchymal tumors that may mimic fibrosarcoma. This review article will summarize the current state of our knowledge about strictly defined adult fibrosarcoma and discuss important entities in its differential diagnosis, including various fibrosarcoma variants, monophasic synovial sarcoma, and other potential mesenchymal and non-mesenchymal mimics.
Overview This article will review the subject of fibrosarcoma (FS), concentrating on the entity referred to by the World Health Organization as “Adult Fibrosarcoma” 1. This term refers
to a specific entity, which is by definition a diagnosis of exclusion. Fibrosarcomas in children represent a clinicopathologically and genetically distinct entity, and are beyond
This article is protected by copyright. All rights reserved.
Accepted Article
the scope of this article. In addition to adult FS, this article will also address selected other important fibroblastic sarcomas that must be distinguished from adult FS, including low-grade fibromyxoid sarcoma, sclerosing epithelioid fibrosarcoma, and fibrosarcomatous dermatofibrosarcoma protuberans. Other spindle cell malignant neoplasms that enter the differential diagnosis of adult FS, in particular monophasic synovial sarcoma will also be addressed.
Historical Background Adult fibrosarcoma (FS) was once considered to represent far and away the most common soft tissue sarcoma in adults, reportedly accounting for 66% of all sarcomas seen at Mayo Clinic between 1910 and 1930 2. Indeed, Meyerding and colleagues seem
not to have considered the possibility of other tumors mimicking FS. However, this viewpoint began to be challenged, beginning with Dr. Arthur Purdy Stout’s landmark study of FS, published in the first volume of Cancer in 1948 3. Critically, Stout
emphasized the numerous morphologic mimics of FS, including what we would now recognize as variants of liposarcoma, rhabdomyosarcoma, synovial sarcoma, malignant peripheral nerve sheath tumor, and fibromatosis, commenting that “there is little cause for wonder therefore that many malignant sarcomas of other sorts have been reported as fibrosarcomas…” 3. Stout’s observations represent a critical “intellectual leap” in soft tissue pathology, specifically the recognition that FS was inherently a diagnosis of exclusion.
This article is protected by copyright. All rights reserved.
Accepted Article
The impact of Stout’s work is illustrated in 4 subsequent series of FS from the Mayo Clinic. The first major study of FS from Mayo Clinic in the “post-Stout” era, by Pritchard and colleagues in 1974, clearly demonstrates Stout’s influence 4. These authors
reviewed a series of 330 tumors diagnosed as FS between 1910 and 1968 (including Meyerding’s cases) and excluded over 33% as representing something other than FS. Pritchard and co-workers regarded only 12% of soft tissue sarcomas seen at Mayo Clinic during this time period to represent FS 4. Fifteen years later another series of
putative FS from Mayo Clinic (including 87 of 199 cases previously reported by Pritchard et al) again reclassified the majority of these cases as likely representing something other than FS 5. Finally, Bahrami and Folpe’s 2010 series of 163 Mayo Clinic cases previously classified as FS found only 16% to actually represent FS when studied with modern immunohistochemical and molecular genetic techniques 6. Thus, the
incidence of FS has declined dramatically over the past 7 decades, with recent SEER data showing it to account for only 3.6% of sarcomas arising from soft tissues 7. Even
these data overstate the incidence of adult FS, however, and it is likely that strictly defined cases account for
