Supernumerary ring chromosome in a Bednar tumor (pigmented dermatofibrosarcoma protuberans) is composed of interspersed sequences from chromosomes 17and 22: A fluorescence in situ hybridization and comparative genomic hybridization analysis

Cytogenetic analysis of Bednar tumor (pigmented dermatofibrosarcoma protube rans) has not been reported previously. Here, we report the identification of a supernumerary ring chromosome in a Bednar tumor by chromosome painting with fluorescence in situ hybridization (FISH) and comparative genomic hyb ridization (CGH). Chromosome painting with FISH demonstrated that the super numerary ring chromosome was composed of discontinuous, interwoven sequence s from chromosomes 17 and 22. Amplification of chromosomes 17 and 22 sequen ces was confirmed by CCH. These results indicate that Bednar tumor and derm atofibrosarcoma protuberans are characterized by the same chromosomal featu res. To our knowledge. this is the first report that the ring chromosome in Bednar tumor is composed of amplified material from chromosomes 17 and 22. (C) 2001 Wiley-Liss, Inc.