Molecular Cytogenetics Detect an Unbalanced t(2;13)(q36;q14) and PAX3-FOXO1 Fusion in Rhabdomyosarcoma With Mixed Embryonal/Alveolar Features

Pediatr Blood Cancer. 2015 Dec;62(12):2238-41. doi: 10.1002/pbc.25664. Epub 2015 Jul 14.

Abstract

Distinguishing between alveolar rhabdomyosarcoma (ARMS) and embryonal rhabdomyosarcoma (ERMS) is crucial because treatment and prognosis are different. We describe a case of paratesticular rhabdomyosarcoma (RMS), which was classified as mixed ERMS/ARMS. Fluorescence in situ hybridization (FISH) detected losses of 3'PAX3 and 5'FOXO1, suggesting they had undergone an unbalanced rearrangement that probably produced the PAX3-FOXO1 fusion. Double-color FISH and reverse transcription-polymerase chain reaction (RT-PCR) revealed PAX3-FOXO1, which is characteristic of high-risk RMS. This finding highlights the importance of supplementing histology with genetics so that atypical RMS is appropriately classified and patients are correctly stratified and treated.

Keywords: PAX3-FOXO1; mixed ERMS/ARMS; paratesticular localization.

Publication types

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

MeSH terms

  • Child, Preschool
  • Chromosomes, Human, Pair 13 / genetics*
  • Chromosomes, Human, Pair 2 / genetics*
  • Humans
  • Male
  • Oncogene Proteins, Fusion / genetics*
  • Paired Box Transcription Factors / genetics*
  • Rhabdomyosarcoma, Alveolar / genetics*
  • Rhabdomyosarcoma, Embryonal / genetics*
  • Testicular Neoplasms / genetics*
  • Translocation, Genetic*

Substances

  • Oncogene Proteins, Fusion
  • PAX3-FOXO1A fusion protein, human
  • Paired Box Transcription Factors