Although soft tissue sarcomas are rare tumors, representing only ± 1 % of all malignant tumors in adults, they remain a challenge to all disciplines in medical treatment and research. Apart from research in all fields of treatment, soft tissue sarcomas are also encountered in several forms of combined modality treatment. Since the appearance of the first volume on soft tissue sarcomas in this series (Soft Tissue Sarcomas, Laurence H. Baker, ed., Martinus Nijhoff Publishers, 1983), a large amount of data has emerged from preclinical as well as clinical in­ vestigations. The present volume provides an up-to-date review of the state of the art without duplicating the contents of the earlier volume. In the chapter on pathology it is again indicated that malignant fibrocytic hys­ tiocytoma is at present the most frequently diagnosed type of soft tissue sarcoma. Nevertheless, sub-typing is less important for the prognosis than grade. Recently, grading has been defined better, permitting a more common use of this prognostic factor. However, the experience of the pathologist is most important for adequate grading. The pathologist will need an adequate biopsy to perform his investiga­ tions. Cytology is not sufficient for diagnosis. However, for confirmation of metastatic lesions, cytology may provide enough information. Some new tools have been added to the equipment of the pathologist.