Primary soft tissue tumours of the lung

Although primary mesenchymal tumours of the lung are rare, a working knowledge of the morphology, clinical features, genetic abnormalities, and appropriate ancillary studies applicable to these lesions will be very helpful to practising pathologists who review pulmonary material. This is especially important since mesenchymal neoplasms frequently enter the differential diagnosis of other more common pulmonary tumours with sarcomatoid appearance, including sarcomatoid carcinoma and mesothelioma. This review will cover the key morphologic and clinicopathologic features of primary soft tissue tumours of the lung, including solitary fibrous tumour, synovial sarcoma, inflammatory myofibroblastic tumour, pleuropulmonary blastoma, vascular lesions, and others. A practical approach to the differential diagnosis and appropriate use of relevant immunohistochemical markers and ancillary genetic studies will be discussed.