Cytogenetic Distinction among Benign Fibro-osseous Lesions of Bone in Children and Adolescents: Value of Karyotypic Findings in Differential Diagnosis

Byline: David M. Parham (1,2,3), Julia A. Bridge (4), Janet L. Lukacs (3), Yiling Ding (1), A. Francine Tryka (1), Jeffrey R. Sawyer (1,3) Keywords: bone neoplasms; cytogenetics; fibrous dysplasia of bone; ossifying fibroma Abstract: Benign fibro-osseous lesions of bone (BFOL) comprise a group of clinically distinct entities with significant histologic overlap and often occur in children and adolescents. Because of prior studies indicating that these lesions possess distinct karyotypic abnormalities, we conducted a retrospective review of cytogenetic analyses performed in a series of 16 BFOL in children and adolescents diagnosed at two institutions. These comprised five cases with the diagnosis of ossifying fibroma, four with osteofibrous dysplasia, and seven with fibrous dysplasia arising in the skeleton of 16 children and adolescents. All cases were analyzed using standard G-banding techniques on fresh tumors explanted in tissue culture media. Spectral karyotyping (SKY) and fluorescence in situ hybridization (FISH) were used to analyze selected metaphases of a talar lesion with the histologic features of ossifying fibroma. All four confirmed ossifying fibromas, including the talar lesion, contained clonal aberrations fusing breakpoints on Xq26 and 2q33, and one case with dissimilar histology did not. Three of four osteofibrous dysplasias contained multiple copies of chromosomes 8, 12, and/or 21. All but two fibrous dysplasia cases exhibited either a completely normal karyotype or single cell aberrations. One fibrous dysplasia had subtle chromosomal abnormalities not seen in other cases in the series, and another had complex abnormalities involving multiple chromosomes. Our current and published results indicate that cytogenetics might be of ancillary use in the diagnosis of BFOL and that a characteristic chromosomal arrangement is associated with ossifying fibroma. Author Affiliation: (1) Department of Pathology, Arkansas Children Hospital and University of Arkansas for Medical Sciences, Slot 820, 800 Marshall Street, Little Rock, AR 72202, USA (2) Department of Pediatrics, Arkansas Children's Hospital and University of Arkansas for Medical Sciences, Little Rock, AR, USA (3) Cytogenetics Laboratory, Arkansas Children's Hospital, Little Rock, AR, USA (4) Department of Pathology &amp Microbiology, Pediatrics, and Orthopedic Surgery, University of Nebraska Medical Center, Omaha, NE, USA Article History: Registration Date: 01/01/2003 Received Date: 11/06/2003 Accepted Date: 13/11/2003 Online Date: 17/03/2004 Article note: This research was presented in part at the annual meeting of the United States and Canadian Academy of Pathology, San Francisco, California, USA, March 20--26, 1999.