[Comparative genomic hybridization. A screening method in genetic tumor diagnosis]

Comparative genomic hybridization (CGH) is a new method of screening a tumor for genetic changes. The alterations are classified as DNA gains and losses and reveal a characteristic pattern that includes mutations at the chromosomal and subchromosomal levels. Although DNA from fresh-frozen tissue is recommended as the starting material, archival specimens can also be analyzed. Various examples are presented that illustrate the changes that occur in different tumor entities, and preneoplastic lesions, the differentiation of primary tumors from metastases, and the investigation of tumor cell lines that are resistant to cytostatic drugs. These examples emphasize that CGH can extend the possibilities for genetic diagnosis in tumor pathology.