Genomic instability and recurrent breakpoints are main cytogenetic findings in Hodgkin's disease

Background and Objective, Successful cytogenetic studies In Hodgkin's disea se (HD) are rare, and, except for hyperdiploidy, no chromosome changes typi cal for this disorder have been described. The purpose of this study was to collect cytogenetic information from a new series of lymphoid neoplasms di agnosed either as classical HD or as Hodgkin's like anaplastic large cell l ymphoma (HD-like ALCL), according to the REAL Classification. Design and Methods. We studied 27 cases of HD and 10 cases of HD-like ALCL. Cytogenetic investigation were performed on lymph nodes (35 cases), bone m arrow or pleural effusion. A large screening of slides was performed to det ect abnormal metaphases es despite the low mitotic index of Reed-Sternberg cells, In addition to ours, available published data were analyzed in detai l to Identify recurring cytogenetic events. Results. Metaphases which could be analyzed were obtained in 86.5% of cases , with 59.4% showing abnormal clones. We found a peculiar kind of cytogenet ic instability in which, despite variations in the type of structural rearr angements, chromosome breakpoints were non-randomly distributed, Moreover, from our data plus those collected from literature on HD (total 177 cases), the number of breakpoints was higher in patients in a more advanced clinic al stage. Interpretation and Conclusions, Cytogenetic studies In HD are highly inform ative regarding clonality, provided large numbers of metaphases are examine d. Based on karyotype, genetic changes in HD and HD-like ALCL are similar. Results are consistent with a high degree of chromosomal instability and pr edominance of hyperdiploid complex karyotypes. Chromosome breakpoints are n on-randomly distributed and more numerous in advanced clinical stages. (C) 1999, Ferrata Storti Foundation.