RELEVANCE OF CYTOGENETIC AND FLUORESCENT IN-SITU HYBRIDIZATION ANALYSES IN THE CLINICAL-ASSESSMENT OF SOFT-TISSUE SARCOMA

Soft tissue sarcomas are a heterogeneous group of malignant tumors dis playing a wide range of clinical presentations, morphological features , and biological behaviors. These characteristics and the recent devel opment of differentiated treatment regimens for the different types of soft tissue sarcomas call for refined histological classification usi ng additional ancillary approaches such as cytogenetic and molecular g enetic analyses. We coupled classical cytogenetics and fluorescent in situ hybridization (FISH) on both metaphases and interphase nuclei to show the feasibility of this approach to characterize tumor type-speci fic chromosome rearrangements in soft tissue sarcomas of different his totype. In 35 cases analyzed, we detected the presence of specific chr omosome rearrangements such as t(X;18) in synovial sarcoma (SS), t(12; 16) in myxoid liposarcoma (MLS), t(11;22) in peripheral primitive neur oectodermal tumors (pPNET), t(2;13) in alveolar rhabdomyosarcoma (ARMS ) and ring chromosomes in dermatofibrosarcoma protuberans (DFSP). In s everal cases, the presence of these cytogenetic rearrangements was of help for a differential diagnosis. The FISH analysis using painting pr obes not only confirmed the cytogenetic results but also allowed the i dentification of tumor-specific chromosome changes in those cases pres enting low mitotic index or with poor quality chromosomes. Moreover, i n the absence of analysable metaphases, FISH was successfully performe d on interphase nuclei. Taken together, these results indicate both th e diagnostic and clinical relevance of a molecular cytogenetic analysi s in the study of soft tissue sarcomas. Copyright (C) 1997 by W.B. Sau nders Company.