Molecular Pathology of Soft-Tissue Neoplasms and Its Role in Clinical Practice.

BACKGROUND Soft-tissue neoplasms embody a histologically diverse group of mesenchymal tumors. Oftentimes the histopathological diagnosis of soft-tissue tumors is challenging due to overlapping pathological features. METHODS We reviewed the current and most importantly known recurrent or tumor-specific genetic abnormalities involving soft-tissue tumors, focusing on how they are useful in working up differential diagnoses and the relevance of potentially targeted therapies. RESULTS Molecular diagnostic tools have shown great advantage as an aid in the differentiation between different soft-tissue tumor entities, providing a potential avenue in the identification of novel therapeutic targets. Gastrointestinal stromal tumor is a well-known example of a soft-tissue tumor with a successful, molecularly driven treatment with response rates of more than 80% in stable disease and partial remission. Classifying soft-tissue neoplasms by their molecular genetic pathology has been considered as molecular testing becomes more integrated into various diagnostic and prognostic algorithms. CONCLUSIONS Molecular pathology provides a unique opportunity for pathologists to play a crucial role in the multidisciplinary care of patients with sarcoma. These opportunities include but are not limited to the appropriate triage of tissue for molecular testing and the integration of molecular testing results, with histological and immunohistochemical findings providing actionable information for the diagnosis, prognosis, and choice of therapeutic modality.