A mesenchymal chondrosarcoma with aberrant nuclear expression of STAT6: a potential diagnostic pitfall

Pathol Res Pract. 2022 Apr:232:153803. doi: 10.1016/j.prp.2022.153803. Epub 2022 Feb 11.

Abstract

STAT6 is usually considered to be a very sensitive and specific immunomarker for diagnosis of solitary fibrous tumor (SFT), being a surrogate of the NAB2-STAT6 fusion gene identified in most cases of this tumor. STAT6 expression has also been reported in rare cases of other soft tissue tumors, such as low-grade fibromyxoid sarcoma, myxoid/round cell liposarcoma, dedifferentiated liposarcoma and deep fibrous histiocytoma. The aim of this study was to report, for the first time, a case of mesenchymal chondrosarcoma showing diffuse aberrant immunohistochemical expression of STAT6. Molecular biology, showing the HEY1-NCOA2 fusion gene, was crucial to rule out SFT.

Keywords: Diagnostic pitfall; HEY1-NCOA2 fusion gene; Mesenchymal chondrosarcoma; NAB2-STAT6 fusion gene; STAT6.

Publication types

  • Case Reports

MeSH terms

  • Biomarkers, Tumor / metabolism
  • Chondrosarcoma, Mesenchymal* / diagnosis
  • Chondrosarcoma, Mesenchymal* / genetics
  • Diagnosis, Differential
  • Humans
  • Immunohistochemistry
  • STAT6 Transcription Factor / metabolism
  • Solitary Fibrous Tumors* / pathology

Substances

  • Biomarkers, Tumor
  • STAT6 Transcription Factor
  • STAT6 protein, human