Current soft-tissue sarcoma classifications.

In order to analyse the impact of modern sarcoma classification criteria, pathological material from 281 extremity soft-tissue sarcomas (STS) was reviewed. The cases were originally diagnosed between 1972 and 1994, and the most frequent diagnoses then were malignant fibrous histiocytoma (MFH) (26%), liposarcoma (21%), fibrosarcoma (11%), and leiomyosarcoma (10%). After reclassification, the proportions had changed significantly, with the largest group now being leiomyosarcomas (20%), liposarcomas (17%), synovial sarcomas (14%), and sarcomas "not otherwise specified" (NOS) (11%). The original diagnosis was changed in 57% of the cases; in particular, the number of fibrosarcomas was reduced from 32 to 6, and MFHs from 72 to 2, with 22 renamed as myxofibrosarcomas; 20 (7%) were found not to be sarcomas. The main reasons for these results are the recent advances in immunohistochemistry (IHC) together with changes in nomenclature. The findings have obvious implications, in particular for retrospective research.