The Diagnosis of Soft Tissue Tumors. The Göteborg Experience

Abstract

Soft tissue tumors are classified on a histogenetic basis. Such a classification, with 15 main histogenetic groups, was established by WHO (1969) under the leadership of Dr. Franz Enzinger. An updated classification has been presented by Enzinger and Weiss in their textbook of soft tissue tumors. This classification comprises some 150 tumors and tumor-like lesions, of which, 30 are malignant soft tissue sarcomas. The subclassification of sarcomas is not based on the degree of cell and tissue differentiation or the histologic grade of malignancy, but is based on differences in histologic structure, age, clinical presentation and localization. For histologic malignancy grading we use a system with 4 grades, basically like the one developed and used at the Mayo Clinic. The grading of soft tissue sarcomas is based mainly on cellularity, cell atypia and the degree of anaplasia, mitotic activity and cell and tissue differentiation, and also on the manner of growth, necrosis and hemorrhage. Soft tissue sarcomas of various types with the same malignancy grade do not necessarily display identical clinical behavior.