Current concepts in the diagnosis of human soft tissue sarcomas

The surgical pathologist is often called upon to make a rapid decision about the malignant potential of a soft tissue tumor. These tumors have specific stromas that support growth and endow the tumor with unique qualities, as well as being manifestations of the phenotypic expression of tumor cells. Collagen, the major protein of the stroma of tumors, is now recognized as a family of proteins, each a different gene product. Immunofluorescence microscopy studies using antibodies directed against purified stromal components, particularly the different type specific collagens, may soon be available in large quantities. These are potentially useful tools for the surgical pathologist not only in making that important decision, but also for developing a classification scheme for human sarcomas. This scheme will inevitably have a more sound biological basis than those currently used.