Soft tissue tumors: new perspectives on classification and diagnosis

Abstract

Background: In recent years, new tumor entities have been described and previously known tumor types have undergone a reassessment. This article offers an overview of recent developments in the classification and interpretation of soft tissue tumors.

Methods: Selective review of publications from 1990 until 2008 from the literature database of the Consultation and Referral Center for Soft Tissue Tumors in Jena. The current status of the classification and morphological diagnosis of these tumors is described.

Results: The description of the biological behavior of soft tissue tumors has become more detailed with the introduction of two intermediate categories ("intermediate, locally aggressive" and "intermediate, rarely metastasizing"). There have also been some changes in terminology. Previously established terms such as "malignant fibrous histiocytoma" or "hemangiopericytoma" will be used much less often in future, because these tumor types have been reinterpreted. The WHO recommends that highly differentiated liposarcoma be renamed "atypical lipomatous tumor." Molecular diagnostic techniques have become firmly established as an ancillary diagnostic method. The importance of molecular tumor characterization for individually tailored therapy is already becoming clear.

Conclusions: Optimal diagnosis is the prerequisite for effective therapy and can be achieved only with state-of-the-art knowledge of the pathology of soft tissue tumors.

Keywords: biopsy; cancer diagnosis; molecular biology; molecular medicine; soft-tissue sarcoma.

Figure 1

Atypical lipomatous tumor: adipocytes of varying size with marked nuclear atypia

Figure 2

Dedifferentiated liposarcoma: alongside structures of an atypical lipomatous tumor, formations of an undifferentiated spindle cell sarcoma are seen