Use of interphase cytogenetics in demonstrating specific chromosomal aberrations in solid tumors - new insights in the pathogenesis of malignant melanoma and head and neck squamous cell carcinoma

The detection of structural and numerical chromosomal aberrations is an imp ortant part of the characterization of tumors and genetic diseases. The dir ect demonstration of DNA sequences in interphase nuclei and metaphases by f luorescence in situ hybridization (FISH) has been termed interphase cytogen etics. It has been proven as a powerful technique to detect specific aberra tions in a wide variety of cell types, including paraffin-embedded tissue. Nowadays a standard method in leukemia and lymphoma, interphase cytogenetic s contributes mainly to the diagnosis in these tumors and helps to classify soft tissue tumors. Therefore FISH is mandatory for the choice of therapy in these tumors. In contrast to the aforementioned, up to now, the value of FISH in solid tumors is mostly limited to pure research and contributes in this way to our understanding of tumor biology. But with the use of paraff in-embedded tissue and the first results obtained, it seems very likely tha t a direct correlation between histological classification and cytogenetic characteristics of solid tumors can be achieved in the near future. This in formation might not only provide insights into tumor biology, but could als o contribute to a different tumor classification, a sort of risk estimation , where we might predict the possible biological behavior of solid tumors. This could greatly influence further therapeutic decisions thus establishin g the FISH technique as an indisputable part in the diagnosis of solid tumo rs.