Evidence of neural differentiation in a case of post-therapy primitive neuroectodermal tumor/Ewing sarcoma of bone

Am J Surg Pathol. 2003 Aug;27(8):1161-6. doi: 10.1097/00000478-200308000-00016.

Abstract

Neural differentiation with the appearance of ganglion-like cells has been reported in untreated primitive neuroectodermal tumor/Ewing sarcoma (PNET/EWS) at peculiar sites, such as the cauda equina, and following treatment. The case is presented here of a 17-year-old girl with a tumor in the iliac bone. An open biopsy was diagnosed as PNET/EWS of the bone. The tumor had the typical morphology of this tumor type and showed diffuse membranous immunoreactivity for CD99, intense immunoreactivity for synaptophysin, and focal immunoreactivity for neuron-specific enolase and S-100 protein. Occasional reactivity for vimentin was evident, while no immunoreactivity for NB84a, Hu, chromogranins A and B, neurofilaments, cytokeratins, and desmin was present. The patient underwent chemotherapy and radiotherapy, followed by right internal hemipelvectomy. The post-treatment residual viable tumor showed a morphologic appearance resembling a neuroblastoma, with immunoreactivity for NB84a, Hu, synaptophysin, and chromogranins A and B, but not for CD99. RT-PCR performed on tumor tissue before and after therapy showed the presence of the EWS-FLI1 fusion transcript, type I in both samples. This case of PNET/EWS is unique in the sense of showing the typical fusion transcript associated with this tumor both in the morphologically typical pretherapy tumor and in the sample from the post-therapy specimen showing neuroblastoma-like features.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Biomarkers, Tumor
  • Bone Neoplasms / genetics
  • Bone Neoplasms / pathology*
  • Bone Neoplasms / therapy
  • Cell Transformation, Neoplastic
  • Disease-Free Survival
  • Female
  • Humans
  • Ilium / diagnostic imaging
  • Ilium / pathology
  • Neoplasms, Second Primary
  • Neuroblastoma / genetics
  • Neuroblastoma / pathology
  • Neuroblastoma / therapy
  • Neuroectodermal Tumors, Primitive / genetics
  • Neuroectodermal Tumors, Primitive / pathology*
  • Neuroectodermal Tumors, Primitive / therapy
  • Oncogene Proteins, Fusion / genetics
  • Oncogene Proteins, Fusion / metabolism
  • Proto-Oncogene Protein c-fli-1
  • RNA, Messenger / metabolism
  • RNA, Neoplasm / analysis
  • RNA-Binding Protein EWS
  • Radiography
  • Reverse Transcriptase Polymerase Chain Reaction
  • Sarcoma, Ewing / genetics
  • Sarcoma, Ewing / pathology*
  • Sarcoma, Ewing / therapy
  • Transcription Factors / genetics
  • Transcription Factors / metabolism

Substances

  • Biomarkers, Tumor
  • EWS-FLI fusion protein
  • Oncogene Proteins, Fusion
  • Proto-Oncogene Protein c-fli-1
  • RNA, Messenger
  • RNA, Neoplasm
  • RNA-Binding Protein EWS
  • Transcription Factors