Advantages and limitations of cytogenetic, molecular cytogenetic, and molecular diagnostic testing in mesenchymal neoplasms

Excerpt

Elucidation of the pathogenesis of bone and soft tissue tumors has been challenging because the genetic events are unique for the different mesenchymal tumor subtypes. However, enormous progress has been achieved with the advancement of cytogenetic and molecular genetic techniques. As a result, relevant oncogenes and tumor suppressor genes have been identified and localized, and new gene constructs and their protein products that result from translocations during sarcoma genesis have been determined. The identification of tumor-specific genetic markers for bone and soft tissue tumors, such as Ewing’s sarcoma, has added a new dimension to the formulation of a diagnosis and the resolution of cellular origin. Many of the genetic markers appear to have prognostic value, and studies to determine their potential applications as specific therapeutic targets are in progress. Three common genetic approaches used to identify mesenchymal tumorspecific abnormalities are conventional cytogenetic, molecular cytogenetic (fluorescence in situ hybridization, or FISH) and reverse transcription-polymerase chain reaction (RT-PCR) analyses. In this instructional lecture, emphasis is placed on the practical applications of each of these techniques, including their advantages and limitations. Certain case presentations are included to illustrate the integration of traditional histopathological and genetic approaches and serve as useful paradigms. …