The role of cytogenetics and molecular genetics in soft tissue tumour diagnosis-a realistic appraisal

Molecular genetic and cytogenetic analysis has revealed that many soft tissue tumours, both benign and malignant, carry simple, reproducible karyotypic aberrations that are tumour-specific. Many of these mutations are chromosomal translocations and the resulting fusion gene products have been cloned. Classification, diagnosis and prognostication of soft tissue tumours has already been influenced by these genetic findings. Furthermore, examination of fusion gene products has helped increase our understanding of the molecular pathogenesis of soft tissue tumours and will hopefully aid in the development of new therapeutic agents. However, in current 'routine' practice, it remains to be defined when molecular genetic and cytogenetic techniques should be used, which technique should be used and how testing should be performed. Herein we briefly review the impact that cytogenetic and molecular genetic analysis has had on soft tissue tumour pathology and discuss both the benefits and limitations of these techniques in the current practice of diagnostic pathology.