Fusion of COL1A1 exon 29 with PDGFB exon 2 in a der(22)t(17;22) in a pediatric giant cell fibroblastoma with a pigmented Bednar tumor component. Evidence for age-related chromosomal pattern in dermatofibrosarcoma protuberans and related tumors

Cancer Genet Cytogenet. 2002 Apr 15;134(2):156-61. doi: 10.1016/s0165-4608(01)00617-3.

Abstract

In contrast with classic dermatofibrosarcoma protuberans (DP), genetic information about the juvenile or pigmented variant forms of DP, so-called giant cell fibroblastoma (GCF) and Bednar tumor (BT), is limited. In the sole karyotyped case of BT a supernumerary ring containing chromosomes 17 and 22 sequences, similar to DP rings, was reported, whereas in three GCF cases, t(17;22) or der(22)t(17;22) with COL1A1-PDGFB fusion involving exons 11, 40, and 47, respectively, have been described. Here, we report the first cytogenetic and molecular analysis of a tumor from a 5-year-old child that contained both GCF and BT components. The karyotype and molecular analyses confirmed the common histogenetic origin between DP, GCF, and BT in showing the presence of a der(22)t(17;22) fusing the COL1A1 exon 29 to PDGFB exon 2. Because COL1A1 exon 29 has been involved previously in gene fusion with PDGFB exon 2 in several cases of adult or infantile DP presenting either t(17;22) or ring chromosomes, our results support the concept that DP, GCF, and BT are morphologic variants of a same entity, rather than distinct tumors. Of interest, our findings give prominence to the relation between patient age and the chromosomal rearrangement pattern in DP and related tumors. Whereas only a few adult DP cases presented with translocations, all the infantile cases, either DP, GCF, or mixed BT-GCF, as shown here, contained translocation derivatives but not ring chromosomes. All the ring chromosomes were observed in adult cases. With respect to cytogenetic studies, DP, GCF, and BT appear to be a unique model for age-related chromosomal rearrangement progression.

Publication types

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

MeSH terms

  • Adolescent
  • Aging / physiology*
  • Base Sequence
  • Carcinoma, Giant Cell / genetics*
  • Carcinoma, Giant Cell / pathology
  • Child
  • Child, Preschool
  • Chromosomes, Human, Pair 17 / genetics
  • Chromosomes, Human, Pair 22 / genetics
  • Collagen / genetics*
  • Collagen Type I*
  • Collagen Type I, alpha 1 Chain
  • Exons / genetics
  • Genes, sis / genetics*
  • Humans
  • In Situ Hybridization, Fluorescence
  • Infant, Newborn
  • Male
  • Oncogene Proteins, Fusion / genetics*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Ring Chromosomes
  • Skin Neoplasms / genetics*
  • Skin Neoplasms / pathology
  • Translocation, Genetic / genetics*

Substances

  • Collagen Type I
  • Collagen Type I, alpha 1 Chain
  • Oncogene Proteins, Fusion
  • Collagen