Low‐grade fibrosarcoma—report on 39 not otherwise specified cases and comparison with defined low‐grade fibrosarcoma types
- 17 July 2006
- journal article
- research article
- Published by Wiley in Histopathology
- Vol. 49 (2) , 152-160
- https://doi.org/10.1111/j.1365-2559.2006.02480.x
Abstract
Low-grade fibrosarcomas are tumours that mainly affect the extremities and trunk of adults of either sex. Among these, low-grade fibromyxoid sarcoma (FMS), hyalinizing spindle cell tumour with giant collagen rosettes (HST) and sclerosing epithelioid fibrosarcoma (SEF) are well-established entities. In this study, our aim was to describe a group of low-grade fibrosarcomatous tumours, which could not be encompassed by these entities. These low-grade fibrosarcomas, not otherwise specified (FNOS) were provisionally designated as 'fibrosarcoma, low-grade fibroblastic type'.In the soft tissue tumour registry we found 39 FNOS (46%), 31 FMS (36%), 11 SEF (13%) and four HST (5%). FNOS occurred in older patients than FMS (mean age 56.3 years versus 33.7 years). They mainly showed fibrous features, but myxoid areas could also be seen. While cells tended to be loosely arranged in the myxoid areas, densely packed sheets with a storiform pattern, fascicular arrangements or regions without a defined growth pattern were observed in the fibrous areas. However, neither whirling nor swirling patterns were found. Arcade-like vessels were not visible; pseudolipoblasts did not occur. FNOS exhibited increased atypia and mitotic count compared with the other sarcomas studied [FNOS, mean value 4.6 mitoses/10 high-power field (HPF); FMS, 0.7/10 HPF). Follow-up data were available in 21 FNOS patients. In seven cases (33.3%), local recurrences were reported. Three patients (14.3%) developed metastases and all of them died of tumour.The term 'fibrosarcoma, low-grade fibroblastic type' should be used as a diagnosis of exclusion. Further studies should elucidate whether it represents a distinct fibrosarcoma type.Keywords
This publication has 19 references indexed in Scilit:
- Low‐grade fibromyxoid sarcoma versus low‐grade myxofibrosarcoma in the extremities and trunk. A comparison of clinicopathological and immunohistochemical featuresHistopathology, 2004
- Spectrum of Low-Grade Fibrosarcomas: A Comparative Ultrastructural Analysis of Low-Grade Myxofibrosarcoma and Fibromyxoid SarcomaUltrastructural Pathology, 2004
- Low-grade Sarcomas with CD34-Positive Fibroblasts and Low-Grade Myofibroblastic SarcomasUltrastructural Pathology, 2004
- Sclerosing Epithelioid FibrosarcomaThe American Journal of Surgical Pathology, 2001
- Low-Grade Fibromyxoid Sarcoma and Hyalinizing Spindle Cell Tumor With Giant RosettesThe American Journal of Surgical Pathology, 2000
- Low-Grade Fibrosarcoma With Palisaded Granulomalike Bodies (Giant Rosettes)The American Journal of Surgical Pathology, 1999
- Low-Grade Myofibroblastic SarcomaThe American Journal of Surgical Pathology, 1998
- Hyalinizing Spindle Cell Tumor With Giant RosettesThe American Journal of Surgical Pathology, 1997
- MyxofibrosarcomaThe American Journal of Surgical Pathology, 1996
- Sclerosing Epithelioid FibrosarcomaThe American Journal of Surgical Pathology, 1995