Dedifferentiated liposarcoma with rhabdomyoblastic differentiation

Virchows Arch. 2005 Nov;447(5):835-41. doi: 10.1007/s00428-005-0025-0. Epub 2005 Jul 13.

Abstract

Dedifferentiated areas of dedifferentiated liposarcoma (DDL) usually show malignant fibrous histiocytoma (MFH)- or fibrosarcoma-like features and lack any histologic signs of specific differentiation. However, some reports have demonstrated specific differentiation in these areas, with histologic features resembling those of rhabdomyosarcoma, leiomyosarcoma, and osteosarcoma. We report here a pathologic and genetic analysis of three cases of DDLs with rhabdomyosarcomatous areas. MFH- or fibrosarcoma-like areas of one primary DDL and two recurrent DDLs contained various amounts of rhabdomyoblasts, which were immunoreactive for desmin, myoglobin, muscle actin (HHF-35), and myogenin. An ultrastructural examination demonstrated rhabdomyoblasts with abundant cytoplasm containing thin and thick filaments and Z-bands. By real-time PCR, amplification of mdm2 and cdk4 was confirmed in both well-differentiated and dedifferentiated areas with rhabdomyoblasts of all cases. To our knowledge, only seven cases of DDLs with rhabdomyosarcomatous components have been reported, and furthermore, the genetic profiles of the rhabdomyosarcomatous components in DDLs have not been investigated. This study demonstrates that DDLs with rhabdomyosarcomatous areas have genetic alterations that are common to well-differentiated/dedifferentiated liposarcomas.

MeSH terms

  • Biomarkers, Tumor / metabolism
  • Cell Transformation, Neoplastic
  • Cyclin-Dependent Kinase 4 / genetics
  • Cyclin-Dependent Kinase 4 / metabolism*
  • DNA, Neoplasm / analysis
  • Female
  • Gene Dosage
  • Humans
  • Liposarcoma / genetics
  • Liposarcoma / metabolism
  • Liposarcoma / pathology*
  • Male
  • Middle Aged
  • Neoplasm Recurrence, Local
  • Proto-Oncogene Proteins c-mdm2 / genetics
  • Proto-Oncogene Proteins c-mdm2 / metabolism*
  • Retroperitoneal Neoplasms / genetics
  • Retroperitoneal Neoplasms / metabolism
  • Retroperitoneal Neoplasms / pathology*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Rhabdomyosarcoma / genetics
  • Rhabdomyosarcoma / metabolism
  • Rhabdomyosarcoma / pathology*

Substances

  • Biomarkers, Tumor
  • DNA, Neoplasm
  • MDM2 protein, human
  • Proto-Oncogene Proteins c-mdm2
  • CDK4 protein, human
  • Cyclin-Dependent Kinase 4