title: 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.
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.
authors.affiliation: UF Recherche Clinique 952, Laboratoire de Génétique, Université de Nice-Sophia Antipolis, CHU de Nice, 06202 Nice, France.
authors.forename: Georges
authors.initials: G
authors.lastname: Maire
authors.forename: Ludovic
authors.initials: L
authors.lastname: Martin
authors.forename: Sophie
authors.initials: S
authors.lastname: Michalak-Provost
authors.forename: Gilka J F
authors.initials: GJ
authors.lastname: Gattas
authors.forename: Claude
authors.initials: C
authors.lastname: Turc-Carel
authors.forename: Gérard
authors.initials: G
authors.lastname: Lorette
authors.forename: Florence
authors.initials: F
authors.lastname: Pedeutour
mesh_terms: D000293:Adolescent; D000375:Aging / Q000502:physiology*; D001483:Base Sequence; D018286:Carcinoma, Giant Cell / Q000235:genetics* / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D002886:Chromosomes, Human, Pair 17 / Q000235:genetics; D002892:Chromosomes, Human, Pair 22 / Q000235:genetics; D003094:Collagen / Q000235:genetics*; D024042:Collagen Type I; D000090602:Collagen Type I, alpha 1 Chain; D005091:Exons / Q000235:genetics; D020571:Genes, sis / Q000235:genetics*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007231:Infant, Newborn; D008297:Male; D015514:Oncogene Proteins, Fusion / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012303:Ring Chromosomes; D012878:Skin Neoplasms / Q000235:genetics* / Q000473:pathology; D014178:Translocation, Genetic / Q000235:genetics*
chemical_list: D024042:Collagen Type I; D000090602:Collagen Type I, alpha 1 Chain; D015514:Oncogene Proteins, Fusion; D003094:Collagen