The Diagnosis of Pleural Tumors Other Than Mesothelioma

- Pleural pathology has been dominated by discussions relating to the diagnosis, prognosis, etiology, and management of malignant mesothelioma. However, there exists a diverse group of other neoplasms that involve the pleura; the most common by far is metastatic carcinoma, usually of pulmonary origin. Other metastatic tumors of varied histogenesis do occur but are less common. Primary pleural neoplasms other than diffuse malignant mesothelioma are either uncommon or rare and have received less attention.

- To provide a review of those diverse tumors that can involve the pleura other than mesothelioma in order to facilitate their accurate diagnosis.

- Review of relevant literature published via PubMed and other search engines.

- A wide variety of tumors can involve the pleura. In most cases, the approach of considering the morphologic features with appropriate immunohistochemistry, in the correct clinical context, allows for a confident diagnosis. For a number of those soft tissue tumors that are well recognized in the pleura, such as solitary fibrous tumor, desmoid-type fibromatosis, synovial sarcoma, and epithelioid hemangioendothelioma, novel markers now exist based on an understanding of the individual tumors' molecular characteristics. Primary pleural lymphomas are rare with poor prognosis. They represent localized specific diffuse large B-cell lymphomas, with either post-germinal center B-cell or plasma cell lineage, arising in the context of either immunodeficiency or immune sequestration and with viral infection.