Skeletal EWSR1-NFATC2 sarcoma previously diagnosed as Ewing-like adamantinoma: A case report and literature review emphasizing its unique radiological features

Pathol Int. 2021 Sep;71(9):614-620. doi: 10.1111/pin.13135. Epub 2021 Jun 30.

Abstract

Ewing-like adamantinoma (EAD) is a rare bone tumor. It remains unclear whether EAD belongs to adamantinoma, Ewing sarcoma (ES), or an independent category. Herein, we present a case of femoral sarcoma previously diagnosed as EAD in a 26-year-old woman. We observed amplified EWSR1 and NFATC2 fusion signals using fluorescence in situ hybridization. Prompted by its unique radiological features, we reviewed the current literature on skeletal EWSR1-NFATC2 sarcoma (ENS) and EAD. In addition to the similar histological features, we found that both ENS and EAD displayed similar characteristic radiological features, such as the tendency to occur in the diaphysis of long bones, cortical expansion and buttressing-type thickening, and bone surface involvement with saucer-like erosion without cortical destruction. We believe that these unique radiological features were related to its indolent behavior. Altogether, it is possible that previously reported EAD cases may be neither ES nor the classic adamantinoma but ENS. Further studies are needed to clarify the relationship between EAD and ENS.

Keywords: EWSR1-NFATC2 sarcoma; adamantinoma; bone; diaphysis; radiology.

Publication types

  • Case Reports
  • Review

MeSH terms

  • Adamantinoma / diagnostic imaging*
  • Adamantinoma / pathology
  • Adult
  • Bone Neoplasms / diagnostic imaging*
  • Bone Neoplasms / pathology
  • Female
  • Gene Fusion
  • Humans
  • In Situ Hybridization, Fluorescence
  • NFATC Transcription Factors / genetics*
  • RNA-Binding Protein EWS / genetics*
  • Radiography
  • Sarcoma / diagnostic imaging*
  • Sarcoma / pathology
  • Sarcoma, Ewing / diagnostic imaging*
  • Sarcoma, Ewing / pathology

Substances

  • EWSR1 protein, human
  • NFATC Transcription Factors
  • NFATC2 protein, human
  • RNA-Binding Protein EWS