[Molecular genetics in the diagnosis of bone and soft tissue tumours]

Bone and soft tissue tumours are relatively rare; they make up about 1% of all new cancer cases, but around 10% among children and adolescents.

This review paper is based on searches in Medline and our own experience.

There are a number of subgroups that require considerable experience. At the slightest suspicion of malignancy, no biopsy should be performed locally; the patient should be referred to a hospital with experience with this tumour type. Specific chromosomal aberrations have been described in several benign and malignant tumours; sarcomas may be divided into two subgroups based on cytogenetics, one with near-diploid karyotype and few chromosomal changes, but with specific translocations and one with complex karyotypes and multiple cytogenetic aberrations. Sarcomas should be karyotyped in order to identify chromosomal changes in general, whereas fluorescent in situ hybridisation and PCR are the most common methods for detecting the relevant, specific translocations. Genomic screening techniques, in particular microarray-based, global analyses of gene activities and copy numbers, will lead to smaller sets of informative gene assays that may be used in routine analysis. Gastrointestinal stromal tumour (GIST) is a tumour in the gastrointestinal tract where immunohistochemical analysis of the c-kit receptor and molecular diagnosis of mutations in the corresponding gene is important, as targeted therapy towards mutated versions of this receptor is available.