The role of molecular pathology in soft tissue tumor diagnosis: what the radiologist needs to know.

For both general radiologists and those specializing in soft tissue sarcoma imaging, understanding the importance and basic concepts of molecular pathology is becoming increasingly relevant to current clinical practice. As molecular research identifies the most fundamental causes and markers of disease, diagnostic testing is increasingly focused on the cell nucleus and its genetic material. Identifying molecular abnormalities, such as mutations, deletions, and amplifications, has advanced our ability to diagnose genetic diseases, including a variety of cancers. Over the past two decades, molecular pathology has rapidly evolved, enhancing our understanding of sarcoma pathogenesis, diagnosis, and classification. This progress forms the foundation of the 2020 WHO classification of soft tissue and bone tumors. This article will highlight cases where molecular diagnostics are crucial for the definitive classification and diagnosis of select soft tissue tumors, with MRI correlation and key teaching points.