Updates in the approach to intrathoracic sarcomas

Primary intrathoracic sarcomas constitute a rare, heterogeneous group of neoplasms that occur in the lung parenchyma, pleura, and mediastinum. Although pathologically diverse, they frequently show similar clinical and radiological features, and accurate histopathological diagnosis is therefore crucial for correct management and prognostication. The characterization of sarcomas can be difficult, as there is frequent overlap between the histological patterns of benign and malignant lesions, and between different malignant tumours and with non-mesenchymal neoplasms. This is particularly critical within the thorax, where many spindle cell neoplasms represent tumours of epithelial origin or metastatic disease. Immunohistochemistry and molecular genetic techniques are important ancillary contributors to histological interpretation, but several groups of tumours still lack reliable immunohistochemical markers or reproducible genetic changes. We review the pathology of the major types of intrathoracic sarcoma with reference to clinical factors, morphology, immunohistochemistry, and molecular genetics.