FUS rearrangements are rare in 'pure' sclerosing epithelioid fibrosarcoma

Mod Pathol. 2012 Jun;25(6):846-53. doi: 10.1038/modpathol.2011.214. Epub 2012 Mar 2.

Abstract

Several recent reports have described low-grade fibromyxoid sarcoma with sclerosing epithelioid fibrosarcoma-like areas. We evaluated cases of pure sclerosing epithelioid fibrosarcoma lacking areas of low-grade fibromyxoid sarcoma for FUS rearrangement to determine whether this entity could be related to low-grade fibromyxoid sarcoma. Available formalin-fixed paraffin-embedded tissue of 27 sclerosing epithelioid fibrosarcoma from 25 patients was retrieved and tabulated with clinical information. Unstained slides from formalin-fixed paraffin-embedded blocks were prepared and fluorescence in-situ hybridization was performed using a commercial FUS break-apart probe. The median patient age at presentation was 50 (range, 14-78) years, with 14 males and 10 females. Sclerosing epithelioid fibrosarcoma most commonly involved the extremities (n=8) or chest (n=6). Sixteen patients had a median follow-up of 17 (range, 1-99) months; seven were alive and well at 12 (range, 5-30) months; three alive with disease at 28 (range, 9-99) months; five dead of disease at a median of 22 (range, 1-36) months and one was dead of unknown causes. Twelve patients were known to have metastases; the most common site was lung (n=7), followed by bone (n=3), lymph nodes (n=2) and peritoneum (n=1). Only 2 of 22 (9%) analyzable cases of sclerosing epithelioid fibrosarcoma showed rearrangement in the FUS locus by fluorescence in-situ hybridization. Although cytogenetically confirmed low-grade fibromyxoid sarcoma can have sclerosing epithelioid fibrosarcoma-like areas, FUS rearrangement, which is characteristic of low-grade fibromyxoid sarcoma, appears to be relatively rare in pure sclerosing epithelioid fibrosarcoma.

Publication types

  • Multicenter Study

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Epithelioid Cells / pathology*
  • Europe
  • Female
  • Fibrosarcoma / genetics*
  • Fibrosarcoma / mortality
  • Fibrosarcoma / secondary*
  • Fixatives
  • Formaldehyde
  • Gene Rearrangement*
  • Humans
  • In Situ Hybridization, Fluorescence
  • Male
  • Middle Aged
  • Neoplasm Grading
  • Paraffin Embedding
  • Prognosis
  • RNA-Binding Protein FUS / genetics*
  • Sclerosis
  • Time Factors
  • Tissue Fixation / methods
  • United States
  • Young Adult

Substances

  • Fixatives
  • RNA-Binding Protein FUS
  • Formaldehyde